[2.915 on RPi2] first-run wizard immediately disappears

Not only does hotspot not work (it just repeats asking for the password), but the first-run wizard just immediately disappears from screen, leaving the system in unusable state. I have disabled all browser extensions (Safari and Edge on Mac and iPhone), to no avail. I WAS able to get into the UI only by randomly refreshing and clicking. This was not the case with 2.909, that worked fine.