Hi Jørgen,
I too can confirm that if you send just the SysEx message F0 43 7E 00 23 7F F7 to Genos using the programs SendSx or MIDI-OX, Ending 4 is selected. Similarly the message F0 43 7E 00 03 7F F7 selects Intro 4.
I did notice that on both Genos and Tyros4, the MIDI Receive monitor does not indicate activity on any channel when the messages are sent from the above programs. However when your program is used, the MIDI Receive monitor flashes briefly, first on channel 6, then on all other channels!
I don't have a way of revealing exactly what MIDI messages your program is sending, but could the above suggest that your program is sending channel or reset messages as well as the intended sysex for the style part?
Having said that, it remains a fact that whatever your program is sending, it correctly selects Intro/Ending 4 on the T4 but does not on Genos.
Note that I have no intention of using any program to use the extra parts, my interest is purely out of curiosity!
Regards
Ian