Sooo, I checked on the last couple of flights, and yes, my 375 always displays a green ALT. Before, during, after the flight, airborne and groundborne.
Not sure though that it transmits whilst on the ground since I recall having inserted a 30kts speed in the CONFIG, a couple of years ago.
No time today, but since I’m heading towards a “minor” avionics upgrade soon (nope, nil A/P 
), I’ll recheck that stuff.
