R81 works fine but r82+ does not work.
AFAIK, openz is not supported, do you have a subscription ?
I am not have a subscription. Can subscription solve this problem?
We also have one 2 Node cluster with PVE 5.4 for testing but LXC is not really usable in an production environment - virtualization normally simplifies your infrastructure but with LXC it's the other way around, better to go with KVM.