Mines setup like Elhambre.
OT clock out to A4 set to receive.
OT Prog Chg out on ch’x’ to A4 set to receive on ch ‘x’

That’s it, works flawlessly for me.

You only need one midi cable, OT out to A4 in. Are you perhaps sending midi back to the OT?
Are there conflicting midi ch assignments?
Is the Scale setup the same on both machines?
Is chain enabled on the A4?