I don’t know how long ago the problem started. Last weekend I shook the bees through a queen excluder into an empty 10 frame, and found a queen, but still no eggs. I marked the queen, and put her in a 5 frame with the drone brood, and several handfuls of bees.
I don’t know if the found queen was new, but I’m pretty sure I had a marked queen going into winter.
I waited a day and put a new mated caged queen in the 10 frame with the rest of the bees.