usb "Check to make sure the removable drive containing this file is still available"

MacBook Pro Monterey 12.2.1

Word 16.58

SanDisk Ultra Dual Drive Luxe USB Type-C Flash Drive

I save word docs to my usb as they are confidential files that can't be saved on my computer.

As of yesterday, when I try to save a word doc in the usb, I get this message:

"Word cannot complete the save due to a file permission error."

I select "okay" the get this message:

"Check to make sure the removable drive containing this file is still available"

So I save to the same usb location with the same doc name.

THEN...

When I close out the doc I get this message:

"Do you want to save the changes made to the document. Your changes ill be lost if you don't save them." My options are Save, Don't Save, and Cancel

If I click Save, the doc closed then reopens and it just loops like this and I can't close word.

If I click Don't Save it is deleted and can't be recovered.

The only option is to keep renaming the doc every time I want to close word.

I have read and write permission on all docs.

This ONLY happens with Word and not Excel.

And only happens when saving to the usb.

Desktop docs save fine, unless i save them to usb first.

I have been searching and problem solving ALL DAY and nothing.

Please help!!!