I'm unsure what precipitated this. using modern's monumental modpack (1.20.1), for some reason the slot that used to hold the cages is not visible. While you can put the cages into the slot, they no longer function -- bees cannot be removed or added this way. Bees can still enter and exit the hive, but there's no way to do it in a simulated hive other than letting each one come out and chasing after it to capture. Putting bees into the hive nets the same problem: The bee may house itself in a hive that doesn't have its food source (simulated hives)

See images attached.

you need an expansion box on the hive and a sim upgrade in there for that slot to show

Sir this is just an example
here's exactly teh same probelm with the expansion box.

and here's the sturdy cage with a skeletal bee sitting in it, doing absolutely nothing

you're still missing the simulation upgrade