That's odd behavior, haven't seen that before myself. I had to try a few times, the command that finally got it to sync for me was as follows:
rclone sync ./borg crypt:/borg/ --verbose --retries=10 --low-level-retries=20 --drive-chunk-size=32M --protondrive-2fa 123456
then I followed up with a --protondrive-replace-existing-draft=true
to fix the remaining errors.
YMMV. Hope you're able to get it working!
is it not relatively trivial to pre-vet content before they train it? at least with aigen text it should be.