Just had my second iPhone 11 go on me. Confirmed it isn’t just happening with QuadLock mounts. I used a Ram Mount this time (same setup I used with iPhone 7 mentioned in my previous post in this thread). After about 500 miles again, same symptoms as before. Still under warranty, thankfully, but I won’t be experimenting with any more mounts.
I also have had this happen. iPhone 11 mounted to my motorcycle using a QuadLock. I rode probably 400 miles with the phone mounted this way without issues, but then the rear camera started to not be able to focus and makes a buzzing sound as it tries to do so. Front facing camera works fine. I had an iPhone 7 for years prior and rode close to 30k miles with it mounted on the bike and never had an issue.