Problems with C1Pro 15.3 in tethering mode with Fuji GFX100

I recently downloaded v15.3 unto my laptop (Macbook Pro) and then went to a headshot photoshoot for a client. (DON'T do THAT!)

Everything was going well shooting in tethered with my GFX100 & 110mm f2 lens when after approx the 10th shot, I started to receive distorted images much like cartoon characters of my client. Faces were stretched, body parts exaggerated and body twisted.

I tried numerous ways to try and correct error (shutting down laptop, camera etc) to no avail. My client was becoming annoyed with it all. I then checked my SD cards and found that they were OK no distortion whatsoever. At least it wasn't the camera!

When I returned to my office, I downloaded my shots into C1pro on my main computer (Mac Pro 2013) and started the post edit phase. Everything works as expected. 

As such, I can only conclude that there is something not quite right with the tethering mode and GFX100