We've observed a scenario here at Cendio where the Windows client will stop updating graphics: 1. Set up a Windows machine with two identical monitors. 2. Maximize the client on one monitor 3. Drag the client via the title bar to the other monitor, pushing against the top edge so it gets immediately maximized on that monitor At this point it usually stops updating all graphics. It has not locked up though as mouse events are still sent to the server and the cursor will be updated when hovering over different things in the session. It doesn't happen every time unfortunately, but very often. This was seen on a Windows 10 machine with the 4.10.0 client.
Moving the window again unblocks things and everything starts updating again.