I'm shooting a Nikon D5600, 1/200 shutter speed, 100 ISO, f5.6. Using Pocket Wizard triggers on camera and one studio light, with the second light on slave mode. Doing portraits at church for a new directory. Last week I had no problem. Today, intermittently, I would get a dark streak along one side, which suggests to me a sync fail. But my settings aren't changing between shots, and I'm stumped. The triggers have good batteries, the Nikon has a freshly-charged battery, the lights are plugged into a power strip. I'm tethered into LR Classic on my laptop. I've used a similar setup multiple times in the past with no issues. Any help would be greatly appreciated!