[Fujifilm 23mm F2 R WR out of focus areas looks blurry]

Try the same shots on 1/125 with electronic shutter enabled. Than try the same shot on mechanical shutter but with speed 1/200 or 1/250  and check the sharpness. I've found that xt3 shots blurry photos on mechanical shutter between 1/80 and 1/200. I try to solve and figure out the problem but for now no new ideas.

[Fuji 16-80 shutter shock problems]

I have the same problem on my xt3 and 16-80 lens. I have tested today on two bodies of xt3 and always the same effect. Between 1/80 and 1/200 the picture is blurred. I have tested on tripod and with OIS on and OFF, always the same. If you turn on the Electronic shutter everything is perfect. But I don't think it's something wrong with the lens. On the 18-55 lens we have seen the same issue. IMHO there is a problem with the shutter on XT3 generally.