@stormi I only tested with one VM. It crashed a couple of times when the pool master had updates from xcp-ng-updates_testing and the slaves had the updates that were released yesterday. After updating the last remaining slave to updates from xcp-ng-updates_testing, moving the VM resulted in a stuck VM. So I don't think you can draw any conclusions from this, except maybe that you should install the same version on master and slaves.

@stormi Thanks. Installing the update candidate on all hosts and restarting the toolstack works, but only after power cycling the VM once.
xcp-emu-manager is version 0.0.9-1

Is it advisable to stay on the testing repo until the next version? There are some more non-Windows HVM VM's.

I've installed the updates on a pool. Now every time I migrate a pfSense HVM VM within the pool the console is gone and memory usage is at 100%. I did do the following on the pool master: yum update xenopsd xenopsd-xc xenopsd-xenlight --enablerepo='xcp-ng-updates_testing'. The package version also differs from other hosts (0.66.0-1.1.xcpng versus 0.66.0-1.el7.centos). Would that be the cause?