"Prearm: In OSD Menu"?

While setting up/building a new plane (still in bench phase), this new Prearm error came up when test-flipping the arming switch. At the same time, the OSD (analog) vanishes and doesn’t came back even when the switch is back to disarmed.

Is it about the OSD-based parameter menu? I’ve never used it, if I remember correctly it needs 2MB flash, and this is the first time I’m using a 2MB board. Which might explain why I haven’t seen this error before.

But OSD5_ENABLE and OSD6_ENABLE are both = 0, so the feature should be disabled. Also,
OSD_CHAN and OSD_SW_METHOD are both = 0. Arm/Disarm is on CH6.

Together with the OSD vanishing altogether, this looks a bit unintended? I’m using using latest (4.5.0-dev) on Matek F765-WING.