Nothing else wrong with touchpad,keys work well and surface itself works perfectly but every time I try to move the cursor with the touchpad the screen goes black and back to my lock screen and I have to log in again.
Hi Hannah,
We suggest that you follow the steps in this support article to rectify the issue that you're experiencing on your Surface 3 touchpad.
Should the issue still persists, don't hesitate to post back or you may also reach out to our Assisted Support.
Regards.