Thought so. I had faced frequent issues with the Dell KVM console on switching between hosts. The prob is not with the hosts but with the KVM itself. It is also possible that the other host (good host) does support the higher resolution while the problematic host does not and the refresh rate is still carried out for the good host.
Do check out here to refresh the refresh rate Image may be NSFW.
Clik here to view. of the KVM console.
Hope that helps,
zXi