Hey there,
I'm running the -900 No Cabin variant v1.1.6 from iniManager in the latest stable version of MSFS 2024 (Microsoft Store version).
In about every 5th flight, the terrain radar is completely unavailable from the beginning to the end of the flight. Restarting MSFS fixes this for the next flight.
I cannot tell what triggers this, but as you can see in the attached screenshot, I'm flying over some high terrain in Southern France, but the terrain radar is giving me 0/0 values and no terrain graphics on the ND.
Hopefully you can figure this out.