Intermittent loss of joystick control on BlueROV2 Heavy with Navigator

I have a newly assembled BlueROV2 Heavy with Navigator and I am experiencing an intermittent loss of joystick control during dives.

The joystick works normally at first, but during underwater operations the ROV sometimes stops responding to joystick inputs. This happened several times during one dive at depths of around 10–35 m.

When this happens, Depth Hold or Stabilize still works and the ROV continues holding depth/heading, but manual control is lost.

I can restore control by using the mouse to Disarm and then Arm again. After re-arming I also sometimes hear the warning:

“Compass performance degraded”

Has anyone experienced similar behavior or knows what could cause this?