Midi note B below middle C is being played as Eb (below middle C) in the region only

When I'm recoding midi I'm running into a very strange problem..... randomly the B below middle C gets re-routed to Eb (below middle C). It shows right visually in the region, and when I go back to the controller and play the B note it plays correctly but when playing back the region it plays the Eb. Sometimes it will play back correctly but after a while it will happen and when it happens there is no way to make it do anything else....i tried other plugins , other tracks but it stays the same. Again, when you open the region to look at the midi, the midi notes are in the right place, if I click on the Bb note in the region it plays an Eb but if I go to the controller and play a B it plays a B...???. I have looked through everything to try and find anything that would be causing this but haven't found any reason for this.... it is very strange that it is only happening to one note and it always does the same thing....B to Eb....