Internal GM synth on Mac does not work

[neuwirthe]

On MacOS 15.2 on MacStudio with M1 Max both with 0.91 stable and with 0.92 nightly midi out to Internal GM synth does not work. I tested with a simple patch connection notein and noteout directly, using a midi keyboards as input. In both cases, i just jet white noise whit lasts about one second after the key is released.

Incidentally, I noticed that plugdata and MainStage do not coexist reasonably.
MainStage seems not to be able to be configure for the from plugdata input.
With Logic Pro, things work.