I have my collection on NAS, so dont know if this plays a role, but here is is what I see happening.

I have organised my collection by creating folders based on Year. I am trying to find duplicates within the same year folder. So in similarity I select the folder and all its subfolder and set a criteria to 90% to 10%. Do a search and this populates the let pain with list of photos that are duplicate. Clicking on one entry at a time I can select the duplicate for that entry in the Thumbnails panel and delete them off.. This works well. I did try to select multiple entries from the Duplicates pane, and when I select the duplicates for all of the selection from the thumbnails and move to trash, it seems like the entire selection doesnt get honored. Only the first two entries get removed from the duplicates pane. This seems like a bug. Anyone else experienced this? How do I raise a bug... am new to KDE in general

I am not sure about the actual files for the rest of the selection. I think they do get actually deleted from the folder in NAS, but it has become very confusing since the duplicates pane still keeps showing things that I might have already deleted.

So it seems like the # of items retained is half that of selected. For eg if I select 10 items from the duplicates panel, each with 2 duplicates, upon deleting the 20 duplicates, the last 5 items are still listed in the duplicates panel.