Thank you for replies.
That error message rejecting the lxc copy was obviously from the older version as Stéphane replied.
The target is running on Ubuntu 20.04.1. Currently source lxd snap package is running on Ubuntu 18.04.5 where lxd snap is not installed or refreshed automatically. I do upgrades to the source lxd snap manually. My strategy however was that I upgrade the target lxd (lxd backups) normally from the distribution installed image default Ubuntu 20.04.1 snap channel. I was surprised the default Ubuntu 20.04.1 was using channel 4.0/stable and not latest/stable. Is this channel 4.0/stable normal for Ubuntu 20.04.1 distribution?
According to this the I don’t need to do anything
but how about the new snap lxd releases? Should I keep the target (backup server) in the channel 4.0/stable or ‘snap install lxd --channel=latest/stable’ ?
I expected to see the new feature releases on the backup server and then prepare manually upgrades for development sources and production. I am not 100% sure about my upgrade strategy.
Thanks