diff --git a/.github/ISSUE_TEMPLATE/bug_report.yaml b/.github/ISSUE_TEMPLATE/bug_report.yaml
index 5e936c5ec..dcc3f0a97 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.yaml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yaml
@@ -10,16 +10,25 @@ body:
         installation. If you're having trouble with installation or just looking for
         assistance with using NetBox, please visit our
         [discussion forum](https://github.com/netbox-community/netbox/discussions) instead.
+  - type: dropdown
+    attributes:
+      label: Deployment Type
+      description: How are you running NetBox?
+      options:
+        - Self-hosted
+        - NetBox Cloud
+    validations:
+      required: true
   - type: input
     attributes:
-      label: NetBox version
+      label: NetBox Version
       description: What version of NetBox are you currently running?
       placeholder: v3.6.6
     validations:
       required: true
   - type: dropdown
     attributes:
-      label: Python version
+      label: Python Version
       description: What version of Python are you currently running?
       options:
         - "3.8"
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 301fac079..471846427 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -36,6 +36,8 @@ NetBox users are welcome to participate in either role, on stage or in the crowd
 
 ## :bug: Reporting Bugs
 
+:warning: Bug reports are used to call attention to some unintended or unexpected behavior in NetBox, such as when an error occurs or when the result of taking some action is inconsistent with the documentation. **Bug reports may not be used to suggest new functionality**; please see "feature requests" below if that is your goal.
+
 * First, ensure that you're running the [latest stable version](https://github.com/netbox-community/netbox/releases) of NetBox. If you're running an older version, it's likely that the bug has already been fixed.
 
 * Next, search our [issues list](https://github.com/netbox-community/netbox/issues?q=is%3Aissue) to see if the bug you've found has already been reported. If you come across a bug report that seems to match, please click "add a reaction" in the top right corner of the issue and add a thumbs up (:thumbsup:). This will help draw more attention to it. Any comments you can add to provide additional information or context would also be much appreciated.
diff --git a/docs/release-notes/version-3.6.md b/docs/release-notes/version-3.6.md
index 10e93be1e..a4234f8dd 100644
--- a/docs/release-notes/version-3.6.md
+++ b/docs/release-notes/version-3.6.md
@@ -2,6 +2,19 @@
 
 ## v3.6.7 (FUTURE)
 
+### Enhancements
+
+* [#14390](https://github.com/netbox-community/netbox/issues/14390) - Add `classes` parameter to `copy_content` template tag
+
+### Bug Fixes
+
+* [#14249](https://github.com/netbox-community/netbox/issues/14249) - Fix server error when authenticating via IP-restricted API tokens using IPv6
+* [#14392](https://github.com/netbox-community/netbox/issues/14392) - Fix bulk operations for plugin models under admin UI
+* [#14397](https://github.com/netbox-community/netbox/issues/14397) - Fix exception on non-JSON request to `/available-ips/` API endpoints
+* [#14401](https://github.com/netbox-community/netbox/issues/14401) - Rack `starting_unit` cannot be zero
+* [#14432](https://github.com/netbox-community/netbox/issues/14432) - Populate custom field default values for components when creating a device
+* [#14448](https://github.com/netbox-community/netbox/issues/14448) - Fix exception when creating a power feed with rack and panel in different sites
+
 ---
 
 ## v3.6.6 (2023-11-29)
diff --git a/netbox/extras/forms/model_forms.py b/netbox/extras/forms/model_forms.py
index 83a346420..4e4a6e0de 100644
--- a/netbox/extras/forms/model_forms.py
+++ b/netbox/extras/forms/model_forms.py
@@ -1,4 +1,5 @@
 import json
+import re
 
 from django import forms
 from django.conf import settings
@@ -95,8 +96,8 @@ class CustomFieldChoiceSetForm(BootstrapMixin, forms.ModelForm):
         required=False,
         help_text=mark_safe(_(
             'Enter one choice per line. An optional label may be specified for each choice by appending it with a '
-            'comma. Example:'
-        ) + ' <code>choice1,First Choice</code>')
+            'colon. Example:'
+        ) + ' <code>choice1:First Choice</code>')
     )
 
     class Meta:
@@ -107,7 +108,7 @@ class CustomFieldChoiceSetForm(BootstrapMixin, forms.ModelForm):
         data = []
         for line in self.cleaned_data['extra_choices'].splitlines():
             try:
-                value, label = line.split(',', maxsplit=1)
+                value, label = re.split(r'(?<!\\):', line, maxsplit=1)
             except ValueError:
                 value, label = line, line
             data.append((value, label))
diff --git a/netbox/extras/tests/test_views.py b/netbox/extras/tests/test_views.py
index 43baed077..c8c754777 100644
--- a/netbox/extras/tests/test_views.py
+++ b/netbox/extras/tests/test_views.py
@@ -102,7 +102,7 @@ class CustomFieldChoiceSetTestCase(ViewTestCases.PrimaryObjectViewTestCase):
 
         cls.form_data = {
             'name': 'Choice Set X',
-            'extra_choices': '\n'.join(['X1,Choice 1', 'X2,Choice 2', 'X3,Choice 3'])
+            'extra_choices': '\n'.join(['X1:Choice 1', 'X2:Choice 2', 'X3:Choice 3'])
         }
 
         cls.csv_data = (
@@ -125,6 +125,13 @@ class CustomFieldChoiceSetTestCase(ViewTestCases.PrimaryObjectViewTestCase):
             'description': 'New description',
         }
 
+    # This is here as extra_choices field splits on colon, but is returned
+    # from DB as comma separated.
+    def assertInstanceEqual(self, instance, data, exclude=None, api=False):
+        if 'extra_choices' in data:
+            data['extra_choices'] = data['extra_choices'].replace(':', ',')
+        return super().assertInstanceEqual(instance, data, exclude, api)
+
 
 class CustomLinkTestCase(ViewTestCases.PrimaryObjectViewTestCase):
     model = CustomLink
diff --git a/netbox/ipam/api/views.py b/netbox/ipam/api/views.py
index 662b393de..8e815817f 100644
--- a/netbox/ipam/api/views.py
+++ b/netbox/ipam/api/views.py
@@ -1,3 +1,5 @@
+from copy import deepcopy
+
 from django.core.exceptions import ObjectDoesNotExist, PermissionDenied
 from django.db import transaction
 from django.shortcuts import get_object_or_404
@@ -290,7 +292,7 @@ class AvailableObjectsView(ObjectValidationMixin, APIView):
                 )
 
             # Prepare object data for deserialization
-            requested_objects = self.prep_object_data(requested_objects, available_objects, parent)
+            requested_objects = self.prep_object_data(deepcopy(requested_objects), available_objects, parent)
 
             # Initialize the serializer with a list or a single object depending on what was requested
             serializer_class = get_serializer_for_model(self.queryset.model)
diff --git a/netbox/ipam/forms/model_forms.py b/netbox/ipam/forms/model_forms.py
index bfd4f952d..41b31dc76 100644
--- a/netbox/ipam/forms/model_forms.py
+++ b/netbox/ipam/forms/model_forms.py
@@ -818,7 +818,7 @@ class L2VPNTerminationForm(NetBoxModelForm):
 
     class Meta:
         model = L2VPNTermination
-        fields = ('l2vpn', )
+        fields = ('l2vpn', 'tags')
 
     def __init__(self, *args, **kwargs):
         instance = kwargs.get('instance')
diff --git a/netbox/ipam/tables/l2vpn.py b/netbox/ipam/tables/l2vpn.py
index 8635ab62a..6678d184c 100644
--- a/netbox/ipam/tables/l2vpn.py
+++ b/netbox/ipam/tables/l2vpn.py
@@ -73,12 +73,15 @@ class L2VPNTerminationTable(NetBoxTable):
         orderable=False,
         verbose_name=_('Object Site')
     )
+    tags = columns.TagColumn(
+        url_name='ipam:l2vpntermination_list'
+    )
 
     class Meta(NetBoxTable.Meta):
         model = L2VPNTermination
         fields = (
             'pk', 'l2vpn', 'assigned_object_type', 'assigned_object', 'assigned_object_parent', 'assigned_object_site',
-            'actions',
+            'tags', 'actions',
         )
         default_columns = (
             'pk', 'l2vpn', 'assigned_object_type', 'assigned_object_parent', 'assigned_object', 'actions',
diff --git a/netbox/templates/django/forms/widgets/checkbox.html b/netbox/templates/django/forms/widgets/checkbox.html
index bbe201a29..359657136 100644
--- a/netbox/templates/django/forms/widgets/checkbox.html
+++ b/netbox/templates/django/forms/widgets/checkbox.html
@@ -1,6 +1,7 @@
 {% comment %}
   Include a hidden field of the same name to ensure that unchecked checkboxes
-  are always included in the submitted form data.
+  are always included in the submitted form data. Omit fields names
+  _selected_action to avoid breaking the admin UI.
 {% endcomment %}
-<input type="hidden" name="{{ widget.name }}" value="">
+{% if widget.name != '_selected_action' %}<input type="hidden" name="{{ widget.name }}" value="">{% endif %}
 {% include "django/forms/widgets/input.html" %}
diff --git a/netbox/utilities/forms/widgets/misc.py b/netbox/utilities/forms/widgets/misc.py
index 307031bd8..158b0e67e 100644
--- a/netbox/utilities/forms/widgets/misc.py
+++ b/netbox/utilities/forms/widgets/misc.py
@@ -65,5 +65,5 @@ class ChoicesWidget(forms.Textarea):
         if not value:
             return None
         if type(value) is list:
-            return '\n'.join([f'{k},{v}' for k, v in value])
+            return '\n'.join([f'{k}:{v}' for k, v in value])
         return value
diff --git a/netbox/utilities/request.py b/netbox/utilities/request.py
index 0f8ee9cae..a5ca145e9 100644
--- a/netbox/utilities/request.py
+++ b/netbox/utilities/request.py
@@ -1,4 +1,5 @@
-from netaddr import IPAddress
+from netaddr import AddrFormatError, IPAddress
+from urllib.parse import urlparse
 
 __all__ = (
     'get_client_ip',
@@ -17,11 +18,18 @@ def get_client_ip(request, additional_headers=()):
     )
     for header in HTTP_HEADERS:
         if header in request.META:
-            client_ip = request.META[header].split(',')[0].partition(':')[0]
+            ip = request.META[header].split(',')[0].strip()
             try:
-                return IPAddress(client_ip)
-            except ValueError:
-                raise ValueError(f"Invalid IP address set for {header}: {client_ip}")
+                return IPAddress(ip)
+            except AddrFormatError:
+                # Parse the string with urlparse() to remove port number or any other cruft
+                ip = urlparse(f'//{ip}').hostname
+
+            try:
+                return IPAddress(ip)
+            except AddrFormatError:
+                # We did our best
+                raise ValueError(f"Invalid IP address set for {header}: {ip}")
 
     # Could not determine the client IP address from request headers
     return None
diff --git a/netbox/utilities/tests/test_request.py b/netbox/utilities/tests/test_request.py
new file mode 100644
index 000000000..69f677323
--- /dev/null
+++ b/netbox/utilities/tests/test_request.py
@@ -0,0 +1,28 @@
+from django.test import TestCase, RequestFactory
+
+from netaddr import IPAddress
+from utilities.request import get_client_ip
+
+
+class GetClientIPTests(TestCase):
+    def setUp(self):
+        self.factory = RequestFactory()
+
+    def test_ipv4_address(self):
+        request = self.factory.get('/', HTTP_X_FORWARDED_FOR='192.168.1.1')
+        self.assertEqual(get_client_ip(request), IPAddress('192.168.1.1'))
+        request = self.factory.get('/', HTTP_X_FORWARDED_FOR='192.168.1.1:8080')
+        self.assertEqual(get_client_ip(request), IPAddress('192.168.1.1'))
+
+    def test_ipv6_address(self):
+        request = self.factory.get('/', HTTP_X_FORWARDED_FOR='2001:db8::8a2e:370:7334')
+        self.assertEqual(get_client_ip(request), IPAddress('2001:db8::8a2e:370:7334'))
+        request = self.factory.get('/', HTTP_X_FORWARDED_FOR='[2001:db8::8a2e:370:7334]')
+        self.assertEqual(get_client_ip(request), IPAddress('2001:db8::8a2e:370:7334'))
+        request = self.factory.get('/', HTTP_X_FORWARDED_FOR='[2001:db8::8a2e:370:7334]:8080')
+        self.assertEqual(get_client_ip(request), IPAddress('2001:db8::8a2e:370:7334'))
+
+    def test_invalid_ip_address(self):
+        request = self.factory.get('/', HTTP_X_FORWARDED_FOR='invalid_ip')
+        with self.assertRaises(ValueError):
+            get_client_ip(request)