The mouse cursor can go off screen on Roblox if you have set the monitor scaling above the recommended limit. By default, the limit is set to 100% (depending on the display resolution).

Roblox has a cursor problem when running in xwayland, pressing right click makes the camera move around but the cursor refuses to stay in place. The fix I found is using gamescope and adding ...

To fix An error occurred while starting Roblox Studio, Studio details failed to create key or deploy, Reset your Router, Reset TCP-IP, Disable proxy settings, etc.