Ok, a few weeks ago I checked the strong hive and saw that the queen was laying in 8 frames out of the two brood supers.
I suppose, that queen is raising upp, because there is warmer. In this case you must drop that brood super lower or you sheck the brood supers . It is said "turn supers".
The rest was honey, most of it capped.
You have too little space in your hive.
... happen in only a few weeks. It seems they ate the honey in most of the frames, and the queen layed eggs in there. Now things are switched - with only about 8 frames of honey that isn't capped.
Queen needed more space and bees moved in another place capped honey. Bees are clever.
I know what I saw before - lots of honey, and not very much brood.
Too little space. Or you have lowest supers too cold and empty. Do you have too much ventilation?
Isn't it late in the season though for getting much of a summer honey harvest?
Where you live? Northern hemisphere?
In Finland best honey season is just at the begining?
....is it possible they ate it because it's rained every day (usually in the late afternoon or evening)? Even one frame I'd seen before, one slam FULL of pollen, was basiclly empty. .
Yes, it is possible. If it rains whole month, they consume 10-15 kg honey and many frames pollen.
I got dandelion honey quite much a month ago, but I suppose that 10 kg per hive have vanished to bees' mouths. They need it.