I didn’t have this issue until I cranked logging all the way up, I set pixhawk to log everything possible and then I would get this error. I set logging back to default and so far it’s not come back. Logging takes allot of power from the cup and occansiomally pixhawk has to think hard but is too busy so it makes the power module wait for 10 or more milliseconds and each time that happens you get another slow line. So set logging back to default and use only genuine 3dr parts with pixhawk… I had so many hair pulling issues when I didn’t. Especially with the gps and compass… If it don’t say 3dr on it, good luck!