Hi, I created a brass quintet project from the built-in template. The project comes up in concert pitch and no key signature.
I entered b4 into the 1st B-flat trumpet with the computer keyboard. I then selected the B and made it B-flat with the minus key. When I switched to transposed pitch view, my concert pitch B-flat displays as C-flat. If I change it to C-natural and switch back to concert pitch they now display as B-natural.
When I repeat the process with a key signature containing B-flat, the display works correctly.