Arming fails due to "Prearm: DCM roll/pitch inconsistent by x degrees"

Running an Omnibus f4 Nano V6.1 in my nano goblin and randomly get “prearm: DCM roll/pitch inconsistent by x degrees” when I try to arm. Rebooting is not a guaranteed fix, but I was able to get it to arm a few times by picking up the plane and trying to hold it level. This was after a successful flight where this wasn’t an issue. It looks like tailsitter planes can throw this alarm up if they aquire GPS lock while vertical, but I plugged in the battery each time with the plane horizontal and was careful not to disturb it during startup. Not sure if it’s related, but I am not using a compass for this plane. Any ideas?

you need a compass to VTOL