Chosen Solution
When I was at school, I pulled out my phone and a few times the ringer would turn off on it’s own, and I usually keep it off. It was in the middle of class and it did it a couple of times. How do I make it stop? And I need to keep it off during school hours because I can’t have it ringing in the middle of class.
The mute button may be partially defective, essentially switching itself on/off. You could try to replace the flex yourself. It’s not the easiest repair but doable if you are careful and take your time.
Tape the switch with Gorilla tape just a small piece will do it
