I have a Canon 77D, a Yongnuo 622-TX controller on top of the camera, and a YN622C transceiver with a YN-568EX II speedlight.
This system works perfectly.
Yesterday I bought a YN-685. The problem is that it freezes after 1-5 pops when triggered from the YN622-TX attached to the camera. I went to the local dealership and we tried it together. We tested it with a different YN622-TX attached to my camera and it worked, but it's still freezing when I try it with my YN622-TX. I have tried the latest firmware update but didn't solve it. I also don't have a guarantee for the YN622-TX.
Could anyone tell me what is the best way to trigger both of my flashes off-camera? I don't know how to connect them as master and slave.