For anyone using a Sony mirrorless camera and Godox flashes:
I recently purchased the XPro-S to use with my Sony a6400 and found, to my dismay, that it would not work!
It would shoot with a delay before firing and then stop firing altogether after switching to TTL.
After a useless reply from the online shop I bought it from and an unanswered e-mail to Godox Support, I found someone in a forum describing a similar problem…
Simply disable ‘Red Eye Reduction’ in the camera menu (Camera Settings 1 > Page 10, or Camera Settings > Page 2 on older models such as the a6000), and you’re good to go!
With that done, I can happily report that the XPro-S now works perfectly on my a6400. I heartily recommend it!
More well-known is the fix for banding when using HSS on Godox flashes. When using higher shutter speeds, disable ‘e-Front Curtain Shutter’!