From what I’ve read, I’m not sure that you can sync MIDI on the VL Play GTX as the MIDI capabilities appear to be limited. I tried to download the user manual from TC-Helicon, but their site was off-line this morning.
What I did find is that
MIDI Program Change and CC’s are as follows:
Patch Change - General Program Change
Set Key - 30 (1E in hex)
Set Scale - 31 (1F in hex)
HIT Off/On - 28 (1C in hex) (0-63/64-127 for toggle)
TALK Off/On - 114 (72 in hex) (0-63/64-127 for toggle)
Only settings I can suggest to try is to
Set your GTX to channel 10
Set your GTX filter to None
Set your GTX MIDI Control to MIDI Setting
On your BB, Main Pedal > MIDI Settings > MIDI-Out > Sync: try it with either Enable or Disable to see if either works
Hopefully (I know, what a methodology, right?) someone with a VLP GTX that has things working with their BB can help you more than I’ve been able to . . . .