^^^
Check with an MIDI monitor. In that way it will detect IF and WHICH channel the OT are transmitting on (if any). What did you do when trying to test all midi channels from OT?
Transport and Clock are channel independent, but you need to set the settings correct in regard to what you want to do. Including them.
Audio CC (int, ext or int + ext)
Transport (send and/or receive)
MIDI CLOCK (send and/or receive)
If you are using the MIDI tracks, make sure that CC or whatever settings are “activated” too (its graphics turns inverted).