I have received packages and nucs with queens in small cages with no attendants. If your syrup Is in a boardman feeder it is a long way from the cluster and the bees sometimes don't use them if anything at all Is otherwise available. Does that queen have a candy plug the bees are eating thru so she is released? Often there is tape over it that must be removed before the bees can get at the fondant plugging the hole. I wonder if you need to ratchet down a notch and let those bees get settled in their new home. Constant checking can cause them to go find a tree to live in. I would rattle those bees out of that queen cage onto the entrance if it were me I think. If it is cool they may be short of food and energy and just clustering and waiting to assume ground temperature.