Combining EXS24 presets

[M87]

I want to combine the harpsichord and string presets. I've tried going into edit and copying the zones from one and then pasting them into the other preset. It works in the sense that I press a key and I hear the harpsichord and strings, but they're not playing the same pitch for some reason. What am I doing wrong? I haven't screwed around with tunings or transposing btw. They sound fine together if I open the two patches on separate tracks.