If there is no flow on the bees will not draw out comb. And if there is no flow the queen will stop laying so hence no larve, though I would check again and see if you have a queen because it sounds like they could have swarmed on you. If they are taking syurp that fast then I suspect there is a flow issue. If there is a capped queen cell and you couldn't find a queen I suspect she flew he coup. I wouldn't expect much honey and I would keep the feed on till they build up. I would also inspec the hive without the queen cell for a new queen. If you can't find one then think about combining.
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