TYPO3 Core

In certain situations, the Flexform form gets incorrect overwrite values in the frontend.

If I set up a form and overwrite the finisher settings on it, this content is written into the Flexform field with a generated sheet ID.
When I now change the form it generates a second sheet and my first changes remain parallel in the database.
After the next change to the first form both overrides remain existing, in the frontend the same "<field index=...>" value is used as the later value in the flexform. This allows me to maintain the correct finisher in the backend, but in the frontend (with the same finisher type and field name) the values are taken from the second form.

To reproduce:

1. Create the form with E-Mail Finisher and activate "Override finisher settings" in the content element. For the finisher, overwrite the subject with the following value: "Subject 1".
-> Submit the form. The subject is "Subject 1".
2. As in step 1, create a form and select and overwrite it in the same content element. Here "Subject 2" is selected as the subject.
-> Submit the form. The subject is "Subject 2".
3. Select the first form again in the content element. After sending the form, the e-mail has the subject "Subject 2", although in the overrides in the backend it says "Subject 1".

This problem is checked in latest released 8.7 and latest released 9.5