I am having a strange problem with using a mouse (wireless with USB-A dongle) when the laptop is connected to an external monitor via HDMI. I am using the “join displays” setting on Ubuntu, and the mouse works just fine on the external display, but flickers and is not as responsive on the laptop’s internal display. The issue persists no matter which display I use as the primary. With the external display disconnected, the mouse works just fine on the internal display. Has anyone else run into this or a similar issue?
This sounds like it could be related to this issue in Ubuntu: Cursor flickers on primary display when fractional scaling is enable for dual monitors on Ubuntu Desktop 20.04 - Ask Ubuntu
Does the problem disappear if you change the display scaling setting on the internal display?
That was indeed the problem! Adjusting the scaling worked. I guess I changed too many variables at once in my life by switching to Ubuntu and a new computer at the same time! The laptop is great, by the way! And I really appreciate the quick responses from you and your team.