(This has nothing to do with Email spam.)

I’m writing an Apps Script backup solution.
UserA copies files into a staging folder (under My Drive) and adds UserB as an editor.
UserB reads the staging folder and copies the files to a separate location.
This worked well for months but recently files disappear.
UserA copies 5 files into a folder & can see 5 files, but UserB can only see 3 files.
After hours of head scratching I finally found loads of files under UserB’s Spam folder within Drive (nothing to do with email).
Opening them I see an orange banner with ‘This file is currently in spam’ displayed.

Questions:

1. Can I stop files being moved into Spam folder?
2. Via API, can I trawl spam folder and find any files which were originally under my staging folder?
3. Any other advice/help?

Apparently, this Drive Spam folder was introduced May 2023.

https://workspaceupdates.googleblog.com/2023/05/google-drive-spam-folder.html

Thanks all,
Tony