Mike B,
I had / have the same issue with the grip. Grip had been sent to Fuji, they can't produce the issue, so grip should be working as designed.
Mount grip again and i got stil the same issue, XT1 sent to Fuji, as espected no issues Fiji said.
Mount grip on XT1 and the first shot, XT1 was dead so probleem stil exist.
At Home i put my Fuji with grip mounted on a tripod, put my IPhone in recordinternational mode and switch my XT1 on, still the same issue, while IPhone is still recording and XT1 is power on, i remove the grip and ableyes XT1 is responding.
XT1 and grip are sended to FUJI and they replace the motherboard in it.
I got my Fuji back and of course issue is still available, i went back to shop and they give me another grip to try, yesterday i was making me first photos with this grip and as far i don't have any issues on this moment.
I will take more pictures before i will say: issue solved....
Frustrating how Fuji handles with these kind of issues.
I will keep you informed, best regards,
Peter