Waveeater. first all - Welcome.
Wax moths are usually the secondary problem. A strong robust hive can handle wax moths. I believe you've seen the answer but don't recognize it. The first issue I see is your population became weak for some reason. How old is this hive? What do you do you do to manage mites? Bees will gear down when there's no flow on. Introducing a new queen may have been a good idea, adding brood like you did will help as well. Sometimes new queens will spit, sputter, and misfire before they get it right. If there's no flow on I'd suggest feeding (no entrance feeders) therefore giving them the resources to bounce back. It could be that you've had a drift from one hive to another if they're side by side. If that's the case then swap hive locations in the middle of the day. Hope this helps, keep shooting us questions when you come across an issue.