After upgrading from BIAB2018 to BIAB2021, when I play any existing MGU file over MIDI to my Tyros 4 keyboard then the playback is muffled. If I export the Song as MIDI, and transfer it to the Tyros 4 using a USB stick, then it plays fine on the Tyros 4. And then when I play it in BIAB2021 again it will be perfect and it will continue to play perfectly until I load another song on BIAB2021 or until I reload the BIAB2021 app. After which, if I simply (on the Tyros 4) load that exported MIDI again then BIAB2021 plays perfectly again regardless of which Song is loaded.

The only MIDI cable that is connected to the Tyros 4 is the MIDI IN - so there is no MIDI Thru.

Any suggestions most welcome please as this is a pain.