Validation of non-controlled subfields of linked field doesn't work when subfields are added/removed after the field has been linked

Overview: Validation of non-controlled subfields of linked MARC bib field doesn't work for subfields entered after field has been linked.
Issue reproduces for required/repeatable/undefined rules.

Steps to reproduce:

1. Log in into Snapshot environment as admin user

2. Go to “Inventory” app

3. Find imported “MARC bib” record () and open its detail view pane

4. Click on the “Actions” >> “Edit MARC bibliographic record”

5. Link “240” field with imported “MARC authority” record.

6. Add a subfield which should trigger validation error, ex. add undefined “$3” subfield in the editable box.

   Open

7. Click on the “Save & close” button
   Expected result for step 7: Warn error for undefined “$3” is displayed.
   Actual result for step 7: Warn error for undefined “$3” is NOT displayed.

8. Click on the “Save & keep editing” button.

9. Remove added undefined subfield, ex.: delete “$3”

10. Click on the “Save & close” button
    Expected result for step 10: Warn error for undefined “$3” is NOT displayed.
    Actual result for step 10: Warn error for undefined “$3” is displayed.

See attached screencast:

Open