Hi Ziffa, when I started I got 3 established hives, all were very pissie. That next spring they swarmed after that they were all nice. This year I had a hive that had lots of bees, next inspection not so many, and no brood. I checked for a queen couldn't find one, bought a new queen, installed her and checked in a week. No brood and couldn't find that queen. Called all over area hunting another queen, found one but was a ways off. By then numbers were getting low, caught a swarm and was going to combine with the paper method. When started to tape some paper on top of the queenless hive, I checked one more time, there was brood. They are doing fine now, don't think this is usual, had given up on the hive. Good luck to you and your bees.
I did buy a queen last year, caught swarm lost theirs, got a Cordovan that hive is always gentle.