Hive Time is a management sim about exploring and discovering sustainable balances/responses that can survive fluctuations/disasters, not a strategy game per se (we've been specifically avoiding strategy labels and tags). While it intentionally bucks some management sim conventions, inviting players to respond to (and later plan for) dramatic shifts in dynamics is not one of them.
I haven't come across a situation before where previously working Beesitters stop working for no reason and there aren't any events called "Beesitters randomly stop working for no reason" that I can recall writing. If you'd like to send me an email (address is under the "Technical help" section here on the store page) with a better details-to-snark ratio, I'd be happy to look into whether something is misbehaving and give you some instructions for manually disabling individual events.