Craft CMS - 3.6.11.1 - Why are Assets Backed Up to Temporary Storage?
We have isolated the issue to a crone job connected with the Remote Backup Plugin for Craft.
Commenting out the following stops the daily backup.
# /home/forge/www.example.com/craft remote-backup/volume/create
# /home/forge/www.example.com/craft remote-backup/volume/prune

I think there is an issue with trying to connect to the remote storage location.