fixed json field save issue #14689

netbox/utilities/forms/fields/fields.py

@@ -93,6 +93,8 @@ class JSONField(_JSONField):
     """
     Custom wrapper around Django's built-in JSONField to avoid presenting "null" as the default text.
     """
+    empty_values = [None, '', ()]
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         if not self.help_text: