Can't save Keynote files since Sonoma upgrade

Since I downloaded Sonoma, I can not save any keynote files.

I'm the only user of my mac as well as the admin. I'm logged into the same account that created the original keynote files (it's the only account I have.)

I have also deleted and re-installed Keynote, and no luck.

I get an error stating the files are locked, and to unlock them by clicking on "get info" on the finder file. Well I've done that, and the files are NOT locked, and I have both read and write access to the files.

This is really frustrating.

Please help.