multiple virgins in after swarms is common. bees cleaning off marks also common. bee keepers insisting on marking queens and bees balling queen, or keeper damaging queen, happens.
put a frame of eggs in the one you think is queenless. mark it. in a couple/few days, check it. if there are queen cells with something in them, they are queenless but making one. if there is nothing, she's most likely in there but not laying yet.