Looks like some deformed wings to me in the photos, but I can’t tell for sure. Quite possibly varroa. Next time you’re in the hive, uncap some drone cells, pull the larvae and look for mites. That’s where they’ll be this time of year. We dipped below freezing last night, no pupae being pulled here. I would expect a lack of air (or too much CO2) would do the workers in before the pupae since the workers would have a higher metabolism rate. I would carefully check for varroa.