PA 500 stuck midi notes after song play

[Musicadi]

Hello everyone,

I'm experiencing the following:

The PA 500 is connected to the PC vie USB. Whenever I play a midi file on the PC and the PA is in STYLE PLAY mode, I get stuck midi notes (in my case D), so even after I stop the midi file and start playing the arranger, whatever chord I play, I get a /D. Has anyone else experienced this? Thanks in advance.

Adrian