[ovirt-users] Engine/host communication maybe broken

Hi All, I'm currently facing a situation which I don't know how to resolve and I don't know how that happened. The hosted engine HA part is working fine and the vm starts. It's accessible via the gui and that's it. It's showing some hosts online and some offline. It looks like it's not communication with the nodes anymore to get the latest status or to start task. Is there a cache or something that can be cleared on the engine vm to force a connection the the nodes ? Or is there a way to analyze if communication is really broken ? Any ideas how to start from here ? Thank you, Sven