The same thing happened to me today, I've spent 2h30 on the phone with them, they are not acknowledging the problem, saying it's not a thing with Microsoft Surface Book 3, only with Surface laptop 3. I told them to simply check their Microsoft Community forums, youtube and reddit and that they'd find hundreds of people with the same complaint. Again, repeated it's not a thing with SB3. I would have to pay close to 1000 CAD to have it repaired. It's a small tear very close to the webcam, but now I have hairline tears all over the screen.
I quoted them their warranty: Microsoft warrants that the Microsoft Product will not malfunction due to a defect in materials or workmanship under Normal Use Conditions but they say it's not a defect. Unbelievable.