Hi, thanks for reaching out. My name is Bernard a Windows fan like you. I'll be happy to help you out today, my timezone is UTC +8.
I understand the issue you have, there is nothing to worry I am here to help, are you using a USB-type mouse? or a Bluetooth Mouse? if you are using a USB type, have you tried to insert it into a different USB port just to check? in addition, since it is only happening to your external mouse, it is either the Bluetooth or the USB port that has the issue.
While waiting for your response, can you please check the System logs on the PC so that we can further examine the root cause of the issue?
To do this kindly follow the steps from this link:
https://www.yourwindowsguide.com/2017/12/how-to...
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.
Then please upload it by following the steps from the link.
Let me know how it goes and I hope that helps.
Bernard