Let's change the time and it is showing in "Corrected Time", but when I click on Change All, nothing is changed. Happens with one image selected or multiple images selected. Worked fine in previous LR.
Just tried it again (no reboot, just computer sitting on all night) and it worked. Win 10 Pro, 64 bit. I had tried it a number of times before, both on one photo and on multiple photos, so I am sure it was not a procedural problem. I have noticed a couple of other things that magically disappear after restarting LR or rebooting computer. Very disconcerting! If it happens again, I'll post here.