We attempted a similar configuration using Wasabi S3 cloud storage as the target. What we discovered is that the Lifecyle Rule we created wiped out metadata.json and encryption.json in the root of the bucket once those files were outside the retention window. It was a global rule and I'm guessing that we need to be more precise and use scoped rules that target just the xo-vm-backups, xo-config-backups, and xo-pool-metadata-backups folders. Does that sound like it would work? I have a ticket open as well on this.