Slow unresponsive ROON PC Client

Suddenly my Win 10 PC ROON client is very slow and unresponsive. v1.4 306 64-bit. No issues with iPad client, only windows 10 PC. Lag when pushing Menu or any buttons, album art slow to populate, scrolling wheel - all major delay. Used to be instant response. Reboot of PC did not change, task manager shows no performance issues, all other PC apps work fine, only ROON super slow and unresponsive, very puzzling. Even moving the ROON window can be slow.

Sounds like this issue: