There is another method to delete and replace that MIDI track.
1-erase the MIDI track
2-freeze that track - you will be asked if you want to regenerate that track-say no
3-while frozen regenerate (may not be necessary but I do it to make sure the MIDI track is erased
4-while frozen pick a new MIDI/RT instrument if you want
5-while frozen regenerate (may not be necessary but I do it to make sure the MIDI track does not reset to the original voice- I know I'm paranoid.
6-unfreeze track
7-regenerate and the new sound will be there.

If you only want to erase the track stop at #3.


Why is it that doctors call what they do 'practice'?
If flying is so safe, why do they call the airport, the terminal?

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware