It seems likely this is permanent.
This doesn't make sense. I do not have this problem with any other app. There's something wrong with the way Microsoft is handling files.
In addition, the files Word is claiming it cannot open I can open with every other app. The folder contains web page elements (png, .js, .css, etc). Everyone of those files can be open.
Worse yet, I can even open the individual files using Word. It's onlyfailing when I open the html file that is pointing at the files in the folder.
I don't believe Apple released an OS update that would prevent apps from opening files or require the user to repeatedly grant permission to open them.
This is a bug in Office, and it needs to be addressed.
In my example of opening a saved web page with Word, Microsoft could at the very least show one dialog to grant permission for all 100 files (instead of 100 dialogs each requiring multiple clicks).
I can't even cancel out of this, because I have to click on the cancel button for every file (100 clicks to cancel the open file attempt).