Focus and then recompose does not work. It is mathematically impossible. Read up on "True Focus" as used by Hasselblad.
Focus and then zoom does not work on most zooms.
Bob, the XF also has a dedicated mode for this called AFr (same idea as True Focus).
But it's 100% irrelevant to the OP's question. He's using a wide angle on a far away subject. The geometry difference (that AFr or True Focus address) is completely negligible here.
If I had to guess, the OP was following [AF mode >>> focus on subject >> switch to MF >> recompose >> capture] throughout the shoot without issues, but on this specific sequence of images he forgot the [switch to MF] step and so the XF tried (and failed) to refocus on the sky, resulting in several out of focus images.
If this theory is correct, it highlights that the default settings are not great for the workflow he is using. I would suggest changing the workflow (as explained in my previous post, for example, to use hyperfocus mode), but if this workflow is what he prefers I'd suggest a minor tweak: switch the XF UI to remove autofocus from the shutter release and add it to the rear button. This "AF on demand" tweak would remove the need to switch between AF and MF mode on the lens, which would also eliminate the chance that lens focus changes during that switch.
Again, I'd direct you to your P1 dealer. I would rather have expected they would have walked you through these powerful and practical features of the XF (and the many many many others) during your pre-purchase evaluations or your post-purchase training session, but if not, they can do so now.
