Trouble with object export options window

Dear community,

running InDesign 16.1 on a brandnew MacMini M1 with Big Sur 11.2.1. I've encountered some problems with adding alt-tags to pictures for accessibility via the object export options.

1) Frequently, when I want to add a tag manually, the object export options window will not accept me writing or copying text into it, even though the cursor is clearly visible in the entry field. Instead it will paste the text to the document instead, which is really annoying and also could cause text errors in case I overlook it. This can only be resolved by closing and reopening the options window, which is also really annoying when working through a series of pictures to be tagged.

2) Working with two documents and copy/pasting some of the tags I manually entered in one document into the second one, the object export options window will just go blank and not show any content at all anymore in either of its tabs (see screenshot). Closing and reopening the window or even InDesign doesn't solve the issue. Thrashing my preferences did, but that's not really an option to do every 5 min and makes me loose all my other settings as well.

Does anyone have a solution for this?

Thanks
Carola