I have LR 5.5 and OnOne Perfect Photo Suite 8.5 (PPS) installed.
When I edit the photo in PPS, triggered from LR, then come back to LR, the photo isn't shown, but the original photo shows that another photo is stacked with it. No matter what I do I can't see the photo unless I either (1) close LR and re-open it or (2) click another folder to load other set of images, then go back to the folder I was in.
Actual result: You only see the original photo, even though you've expanded the group.
Expected result: I see both photos, the original one and the edited one in PPS.
I have had the same problem on several occasions and here is what I have found. Look at your folders in the left-hand pane. When this has happened to me, the current folder was listed as "Current Import". You need to change the folder view to the actual folder you are working from and then you will see the additional photos from onOne edits.