This seems to be an issue with devices of varying resolutions. I have across server running on an intel big sur MacBook air and am controlling: 1) older macbook air running High Sierra and across client. 2) iPhone SE 2020 3) iPad mini (latest) Issue scenario 1: If I connect 1 and 2 and allow mouse dragging for both, the mouse movement is very slow and choppy on the MacBook. If I change the iPhone to disable mouse dragging things work fine. If 1 and 3 the issue is not present. Issue scenario 2: If I connect 1, 2, and 3. The performance against the iPad and the MacBook are good, but the mouse movement is slow and jerky against the iPhone. In both of the above cases, I am set to relative coordinate mouse. I have also attempted switching to absolute coordinate, but then get no movement on either the iPhone or iPad if I have them set to absolute.