This is was known bug in V3beta1. I just checked TF V3beta16 and I can once again get to bank 50. You might try turning the pedal off then back on, then re-try setting the banks again. Also, if you didn't upgrade to the latest beta (V3b16 at the moment), you may want to try that. If either of those doesn't work, try doing a reset to factory settings (UM p41).
There have been a few threads about this issue. This link is to one of them.
