If you are trying to enter in chords such as Cb or Fb in Cmajor, Finale will automatically respell the chords to the enharmonic equivalent, B and E due to the Simplify Spelling Option under the Chord Menu.

I run into clients who struggle with this automation all of the time.

To turn it off just go up to your Chord Menu and un-check Simplify Spelling!

See you in the score!