GPS ALT shows MSL correctly-ish until satcount comes up off zero, then shows the barometer's AGL?

When I boot up, and as the GPS is acquiring data (though the “satcount” field still shows 0), I can see the MSL altitude jumping around and getting closer and closer to my actual MSL altitude.


When satcount comes up off zero, the GPS altitude then shows ZERO…in other words, it shows AGL, and in fact, the ALT (barometer?) and ALTASL (GPS?) fields are exactly the same…perfectly in sync as they dance around a few feet.

This says to me that for some reason (and I’ve searched around and came up empty), when the satcount is non-zero, the GPS MSL altitude (ALTASL) switches sources and instead shows the barometer’s AGL altitude.

Is this a bug? (Kakute F7).