Enharmonic when going from Concert Pitch & back

This may have been covered, but I didn't find anyone with my exact problem when searching the forums (close, but not exactly). I am doing a concert band score in the key of Ab, I put a B natural in the 1st Bb Clarinet part, hit the Concert Pitch button and it is correctly moved to an A natural, then hit Concert Pitch again, and it goes to a Cb instead of back to a B natural. I manually put it back to a B natural, but every time I hit the Concert Pitch button twice, it's a Cb again.

It wouldn't be a big problem, except that I have to put the whole score in Concert Pitch to copy/paste between parts that have different transpositions. For example, if I want to put the Alto Sax part in the F Horn part, I have to go to Concert Pitch, copy the Alto Sax part, paste it in the F Horn part, then hit the Concert Pitch button to put everything into the correct key. Every time I hit that Concert Pitch button, it changes that B natural to an A natural, then to a Cb. It happens in other places and on other scores, and it appears to be random for different harmonics with no rhyme or reason that I can see, and it's bugging me to death!