now my Mac apps can’t “Save As” on iCloud drive

So I have an old Macbook Pro running Big Sur that I haven’t used in several months, but I want to get it useable again. It worked fine before, but now whenever I create a file and try to save it to iCloud Drive in any directory other than Documents or Desktop, using any app other than Finder, the app acts as though I don’t have permission to do so. I can move documents around, copy and delete them anywhere using the Finder, I can open a file, make changes, and Save, but if I create a new document or try to export to a new file, the Save As dialog beeps and will only show me the Documents and Desktop folders under iCloud. I can save to one of these directories and then go to Finder to move the new file to the proper directory, no problems. I’m using the same admin account I’ve always used, and I checked to make sure I still had Read/Write permissions, and I do. The problem hold no matter which app I use, other than Finder.

Does anyone have an idea what is happening here, and maybe how to fix it?