Custom Kit, snare drum problems

I made a kit with marching snare drum at C4 and bass drum at F3.
Yesterday everything was fine.
Today, for some reason, my snaredrum insists that the sound and note it has to show and play is snare sidestick. And I can’t for the life of me figure out what the hell is going on.
I’ve tried to delete the percussion part and create a new.
I’ve reloaded the playback template. I’ve double checked that I haven’t set any custom drum notehead.
Could somebody please help?

We would need a file !