Transposing Expression map technique applying to note not using that technique

So here’s the situation.

I made a new technique for my drum set’s h.h to play the foot sound on the top of the staff while keeping the usual bottom of the staff foot h.h. intact. (I had to do this because of a quirk in the drum set I’m using - the foot sound properly stops the open h.h., but the closed sound does not stop the open sound for some reason.) I found a solution but it brought up a different issue.

This all worked …. except the expression map is also transposing my kick drum from C1 to D1 making it play the snare instead of the kick.

For some reason the expression map is applying this technique (and its transposition) to notes that are not using that technique (nor are they programmed to respond to that technique in the kit setup.)

Is there a way to say ‘this technique only applies to h.h., not other instruments’? Is this a bug?