Deletes the contents of text fields when changing the field configuration.

I can't seem to reproduce this. If I don't select override then nothing is triggered. What drupal core version are you on?

I found the reason. I recorded a video. https://drive.google.com/file/d/1FuGiGtAunok-kC0f7CyOoKjPleljjd-x/view?u...

This happens with all types of fields, not just text ones.

Thank you, it appears this is related to translations which is why I couldn't recreate it. I will take a look

Yup, that was it, it wasn't checking for proper values of checkboxes for languages. Try the MR and let me know if works for you as well.

It's all right. Thank you.