I can't reply directly to your post as it errors out.
I'm using the dexpad docking station connected via HDMI cable to an external monitor and via USB to a wireless mouse. The problem also occurs while using the phone as a touchpad which clearly indicates its a driver problem and not a peripheral problem. Despite that I've attempted to swap out the mouse with the same result.
The mouse pointer only appears on the phone and not the external display
@Sumwun Sorry about the reply issue, there's some odd things going on with reply in the Community right now. A ticket has been put in for it.
Try wiping the cache partition on the phone. I just tried the same setup with a wired mouse and was able to see the cursor with and without the mouse connected.
Ya I cleared all that out, cache and the settings, reverted back to default. Only thing I haven't done is a complete wipe on the phone which I'm not inclined to do unless I know for sure this is a one time thing because of the security software I have for work.
It might be worth noting, or this might be an entirely unrealted additional Dex mode problem.
When I connected to my PC at home in virtual dex mode through the USB to USB-C cable, I couldn't breifly use the menu to access the apps. After a reboot it seemed to work HOWEVER, virtual mode only seems to work for a short time before it freezes and locks up my phone with severe distortion on the screen, I have to hard reboot the device to get it unfrozen. However I don't want to dwell on that at the moment, I'm more concerned with the mouse not working.
That's kind of a significant note. I use the virtual DeX regularly with no real issues aside from when I'm doing something resource intensive.
I know you said that the software was up to date but I just want to verify before you reset the phone.
Who is your carrier? Please provide the current Baseband version.