Canon 5D3 flash sync problems.
I have a Cactus V6 on Camera. Camera is set to M at 1/200 sync (max of the camera) When I shoot the camera, the flash has a dark bar at the bottom of the flame (its the shutter curtain) I get this if I use (on the remote flash) a Canon 600EX or a GODOX 860C. No matter what flash I use, I get this. At 1/160 it goes away.. problem is I need to shoot at 1/200. On my older manual Phottix triggers, they worked perfectly at 1/200. Why is the flash sync not at lease 1/200?