Could not replicate the issue on 9.4.x-dev
Steps followed to validate the iss...

Could not replicate the issue on 9.4.x-dev
Steps followed to validate the issue.

- Enable the Language and Interface Translation module
- Got to Languages "/admin/config/regional/language" and add a new language.
- Next go to User interface translation "/admin/config/regional/translate".
- Try to add/update the translation string value.

Am I missing anything as I can see the form does not update the values in Ajax. If its not an Ajax form anymore this won't be an issue.