Fixes: 1) Ensure field verbose_name is converted to lowercase for consistency;

Extra: Adjusted `field_label` initialization to use `.lower()` method for improved uniformity;

core/admin.py

@@ -50,7 +50,7 @@ class RelatedAutocompleteFilter(FieldListFilter):
         self.app_label   = remote.app_label
         self.model_name  = remote.model_name
         self.field_name  = field.name
-        self.field_label = field.verbose_name
+        self.field_label = field.verbose_name.lower()
 
         base = reverse("admin:autocomplete")
         self.autocomplete_url = (