playback midi? bug

everytime i press the play-button in musescore it changes the patches in my line-6 hx-stomp
i am usung ms 3.5, the problem started with the RC. I´m using win10 + the hx-stomp as the sound-decice connected with usb. Einstellungen Ein/Ausgabe API:MME Gerät:Lautsprecher(HX Stomp) nothing in Midi Eingabe +Ausgabe is correct Using this in nigthtly-builds eherything is perfect.
I think the problem started clicking once on Midi-Ausgang HX- Stomp. if i try to chang something in the Ein/Ausgabe stetting after closing it it is resetted again or musescore crashes (at least if i click on Audio + MidiGeräte neu starten or Alle Einstellungen auf Voreinstellungen zurücksetzen.
I Allready deinstalled Musescore completely and made a factory-reset of the HX-Stomp
it seems musecore doent allow me to change the midi-setting i once made even if this isnt shown