You're a sage & experienced old bunch hence I thought i'd put this to you;
I bought some new boots (Grisport Fuse) at the back end of last year, from a long established outdoor shop and took advice from the proprietor re size and fit. immediately did a fair bit of walking in them (up to 8 miles per day) and over the course of a couple of weeks got sore feet.
Barely worn them since but thought i'd do a bit this weekend, did a couple of miles on Friday and 3.5 today and I have sore feet again. The soreness is around the broadest part of the foot, in front of the ankle, it doesn't look bruised, feels sort of like it has been crushed.
I've never had bother with footwear before beyond rubbing, can't decide what to do ie. get some different boots or man up and see if it sorts itself out.