and as has been discussed many times before. The update actually informs people who dare to read to recalibrate the controller if it keeps beeping.Quite possibly the same problem as discussed here...
Mini controller beeps constantly
I just updated the firmware to the Mavic mini and now the controller beeps non stop. I recalibrated both IMU and compass as stated. Still beeps. I initially had a sensor error but that went off after the callibration.mavicpilots.com
Re-calibration of the controller was the fix
recalibrated rc and beeping stop ,After update three days ago /controller keeps beeping / any quick fix