every meizu customer has this problem so welcome to the club. Its not a software glitch so u will have to submit ur phone to the service center.It took meizu 35 days to actually repair my phone that after I forced them to escalate the process, I even had to complain in Indian national consumer forum regarding the service meizu provides and mind it they are very lethargic about everything so u will have keep poking them to service ur phone faster or u will have to wait just like me for 35 days

maybe will release flyme 6.2.0.0G soon, after from China version release it.

Maybe u can try to re-flashing ur phone and don't forget to wipe & back-up your data before.

This is a hardware issue. You will have to give your phone to a service centre to get it fixed. If it is under warranty, it will be fixed for free.