Okay, for the first time ever I'm trying to run two tribes at once. So I can have a nature one and a magic one. I waited until nature was established enough that they have lots of food so I can safely "ignore" them. Whenever I switch back to check on them, it says a new hut has been finished, but it really hasn't. It's still only at 41% - and when I switch back to the new tribe it seems they haven't made any progress at anything.