Replaced the screen and it won't stay attached

What type of adhesive did your friend use? I use tesa tape whenever I repair phones that don’t come with preinstalled adhesive.

Unfortunately, with the dust getting in, the corner won’t go back down unless you use a dab of glass safe super glue. Get a bottle that has a small tip to get in between the glass. Make sure you don’t apply too much.

I usually don’t suggest super glue, but the screen on the Pixel is pretty hard to get up without damaging the screen. Ideally, you’d want to remove the screen and reapply tesa tape.