Re: Advice on recent OAV treatment
Agree with those comments.
Also, because your previous treatments were done when there was brood in the hive you would not have got them all, but now there is little brood there will be more phoretic mites available to be killed.
Wait a few days, and do another treatment. See what the drop is, if it's still uncomfortably high you could even follow that with another.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).