I've been through three X-Pro2's with various issues. The turn off/on being the most common while shooting and I finally gave up and elected a refund. The WiFi issues to Instax and locking up the camera to the point of having to remove the battery occurred on all. The final one, rattled off 4 shots it, camera locked up, no error, would not shut off. Had to remove the battery. Decided this camera is not yet worthy of the Pro in the name. I do hope it is firmware... And no, I do not think the battery is the issue. I used a Fujifilm battery exclusively in two of the three X-Pro2's I had.
All the while I contacted Fujifilm New Jersey U.S.A. and they were respectful and understood. The last thing he said to me is Fujifilm Japan was aware of the issues, but nothing since. I can't recall where, but someone said firmware was coming (facebook or other forum), but I am not convinced it is firmware. I tend to think there may be a problem with the shutter mechanism, mainly because one of the Steve's at Fujifilm NJ mumbled it and I picked up on it. He just said it was possible, but he did not know for sure. I figured the third one would be the charm.
I desire the 1/250th sync speed, the 1/8000 mechanical shutter, and I do believe Fujifilm will address the issues. I will try again in the coming months and watch these forums to see if the chatter dies. I sold one of my 5D Mark III bodies to pre-order the X-Pro2 and that would have had me set with two bodies on the Fuji-X system and I would have been content. I ended up picking up an X-Pro1 to compliment my X-T1 and WOW has it improved since I first handled one... and it was a great price. When you consider what it goes for now, it is a steal of a deal.
Day after I received it, took it to a portrait session for a prom party and pretty much used the X-Pro1 for 80% of the shots with the 35 F1.4... Used some off camera flash and it was killer. Paid for itself that night and some. I did not RTM first, but it only took a minute for me to figure out I had to use the D-pad and not the rear dial to adjust the shutter in 1/3 stops. This will be fine until the X-Pro2 issues get resolved... and I will not part ways with the old X-Pro1. Glad I was late to that party.