Rediscovered the comments at
dyxum which some mention a problem with auto focus at the wide end. Having just tested mine indoors, my sample appears to be affected.

So I'm wondering if other owners here have this too? Should it be considered a fault, or more like a known quirk?
The folding screen really helps with targeting and looking at the focus indicator on the lens at same time

With a target approx 3m away, at 16mm the AF mostly locks at infinity or between infinity and the 3m mark. At a tiny amount of zoom (approx 18mm) it tends to lock just below 3m. Increasing past 24mm or so, it locks regularly at 3m. Going down, once I go below 24mm it goes between 3m and infinity again.
I haven't noticed this before since I haven't taken many shots at the wide end, at the problem focus distance reported to be around 1-3m. But reviewing some photos from last Sunday I see the subjects are just slightly blurry whereas the immediate background is sharper. It seems the depth of field was just enough for me not to notice without looking for it.
At this point I'm undecided on returning it for replacement or not...