Problems with remote triggered flash head

[communityguy]

I recently bought the Sony A7Riii. Loving it so far. 

 

I have set of PocketWizards (TT1 and TT5 for Nikon) and a Nikon flash head. Everything is triggering fine, that's not the problem. In A mode, the flash fires and is captured fine. 

 

But in M mode, the flash never registers at all in the image. It's like the sync is off between the flash and the shutter. I've tried everything I can think: 

 

* Updated the firmware on TT1 and TT5

* Tried all flash settings (rear, fill, slow)

* Searched the menus for anything that might be a sync

 

I've tried another set of lights and its separate trigger. They worked fine. No problems. 

 

Please help! This is driving me nuts and I need to figure out ASAP!