Sometimes the board "forgets" who I am, and I must log in again.
The last few days, any attempt to log in using the "Safari" browser met with an immediate error along the lines of "server reset the connection". Quite reliably, on computers, and on mobile devices. As long as the board remembered me, All was good, but once it "forgot" a particular device, that device remained "forgotten", no matter what I did.
That's with Safari. No such problem on Firefox.
This general weirdness now appears to be over, everything back to normal.