If it is the beeping I think you are referring to, both of my controllers of my two Mavic Air in my fleet started rebooting in flight.
You hear the chirps as if it was just turned on.
In some instances, I will hear loud beeping.
Much louder than RTH beeping.
That would make sense what msinger posted "remote controller sticks were not in the center position when the remote controller was powered on"...because if I was flying and it rebooted, my sticks would not be in the center position.
I have had one turned into service and about to get the other one into service.
Not cool either since they are both a month old.
You might want to recal as suggested but then see if you have the reboot issue.