Not sure how close you are to @Eva but not too far away in central Ohio things are getting a little tight for the bees when it comes to nectar sources.
In addition, to quote @Dawn_SD:
Assuming the above is true, you may also need to feed your bees to help them draw out and fill the frames that you’ve added. In your area there may be significant fall nectar from asters and goldenrod, which will give your bees a late boost before winter.
And always, be vigilant for pests, especially mites.