Ubook Pro (m3) gets very hot. Is it nornal?

Do you have anything between your tablet and the mouse? Like a metal desk or something?

You can also try to change the 2.4 GHz channel used on your WIFI router. It might be an interference issue between your WIFI and Bluetooth.

Do you have any other 2.4 GHz devices running like CCTV, a security system or cordless phone? These can also cause Bluetooth interference issues.

If you take your tablet and Bluetooth mouse to a different location, do they work better?

Also, have you installed the latest Intel WIFI driver as well?