diff --git a/addons/base/views.py b/addons/base/views.py
index cb73a4552db..89951d905f8 100644
--- a/addons/base/views.py
+++ b/addons/base/views.py
@@ -391,9 +391,7 @@ def get_auth(auth, **kwargs):
     waterbutler_data = decrypt_and_decode_jwt_payload()
 
     # Authenticate the resource based on the node_id and handle potential draft nodes
-    nid = waterbutler_data.get('nid')
-
-    resource = get_authenticated_resource(nid)
+    resource = get_authenticated_resource(waterbutler_data.get('nid'))
     # Authenticate the user using cookie or Oauth if possible
     authenticate_user_if_needed(auth, waterbutler_data, resource)
 
diff --git a/api/base/filters.py b/api/base/filters.py
index 4d9bc37a442..30b9ea87a3d 100644
--- a/api/base/filters.py
+++ b/api/base/filters.py
@@ -292,6 +292,9 @@ def parse_query_params(self, query_params):
                             field_name: self._parse_date_param(field, source_field_name, op, value),
                         })
                     elif not isinstance(value, int) and source_field_name in ['_id', 'guid._id']:
+                        # TODO: this is broken since value can be a multi-value str separated by comma; in addition,
+                        #       as for a single-versioned-guid value, the filter is `or` but we need `and`; this will
+                        #       be fixed in [ENG-6878](https://openscience.atlassian.net/browse/ENG-6878).
                         base_guid, version = Guid.split_guid(value)
                         if base_guid is None and version is None:
                             raise InvalidFilterValue(
diff --git a/api/guids/views.py b/api/guids/views.py
index 4a0d1ab4a5b..de9171a0451 100644
--- a/api/guids/views.py
+++ b/api/guids/views.py
@@ -11,7 +11,6 @@
 from api.base.utils import get_object_or_error, is_truthy
 from api.guids.serializers import GuidSerializer
 from osf.models import Guid
-from osf.models.base import VersionedGuidMixin
 
 
 class GuidDetail(JSONAPIBaseView, generics.RetrieveAPIView):
@@ -50,9 +49,10 @@ def get_serializer_class(self):
         return None
 
     def get_object(self):
+        base_guid_str, _ = Guid.split_guid(self.kwargs['guids'])
         return get_object_or_error(
             Guid,
-            self.kwargs['guids'].split(VersionedGuidMixin.GUID_VERSION_DELIMITER)[0],  # .split('_v')[0] to support versioned preprints
+            base_guid_str,
             self.request,
             display_name='guid',
         )
diff --git a/osf/models/__init__.py b/osf/models/__init__.py
index 170f6949a4b..652d94942a9 100644
--- a/osf/models/__init__.py
+++ b/osf/models/__init__.py
@@ -17,7 +17,7 @@
     BlackListGuid,
     Guid,
     GuidVersionsThrough,
-    VersionedGuidMixin
+    VersionedGuidMixin,
 )
 from .brand import Brand
 from .cedar_metadata import CedarMetadataRecord, CedarMetadataTemplate
diff --git a/osf/models/preprint.py b/osf/models/preprint.py
index 6a8c29ce7b5..af689522eea 100644
--- a/osf/models/preprint.py
+++ b/osf/models/preprint.py
@@ -1554,7 +1554,6 @@ def run_accept(self, user, comment, **kwargs):
             versioned_guid.save()
         return ret
 
-    # Override ReviewableMixin
     def run_reject(self, user, comment):
         """Override `ReviewableMixin`/`MachineableMixin`.
         Run the 'reject' state transition and create a corresponding Action.