Villagers and animals have disappeared, from main village.

Logged in last night. I was where I had ended the session before: (x 350) on an iced lake/iceberg, beside a small darkwoods village, where everything was fine.
Swam back to main village (x -115) and ALL my villagers there are gone. Except one.
All animals are gone, even the tethered horses.
Closed app, restarted Xbox. Still gone.
Makes me sad, because I had a librarian trading hall full of excellent trades.

Thumbnail of world still shows my location to be on the iced-over lake.