If you ran the Find Duplicates command and removed all the duplicate photos that PowerPhotos was able to find, but are still seeing other photos in your library that appear to be duplicates, there are a couple things you can try.
If you have some of the additional comparison options selected, which narrow down the possible matches, try disabling all of them and let PowerPhotos do the widest search it can do.
If your duplicates are still not being found, then feel free to contact our technical support and send an example of a pair of photos that look to be duplicates but aren’t being found by PowerPhotos.
The best way to send all the data and metadata for a photos it to select it in PowerPhotos then press command-option-p. This will open up the “Contact Support” window with the photo selected to be sent as an attachment. Just do that for each photo you want to send, then click “Submit” in the support window to send the photos along for us to take a look at to troubleshoot the problem.