With a FB integration we have, it seems that comments are being duplicated. From what I can tell, it happens on a contact that has been active over a longer period of time. So it might be that when the conversation gets reactivated, it pulls the whole history again. In the comment panel on a single contact, I can see that the oldest conversations are duplicated more times. The most recent convos are not duplicated at all.
So I think when new comments are added, it should check if it already exists. Or it needs to not add comments before the last update.

With a FB integration we have, it seems that comments are being duplicated. From what I can tell, it happens on a contact that has been active over a longer period of time. So it might be that when the conversation gets reactivated, it pulls the whole history again. In the comment panel on a single contact, I can see that the oldest conversations are duplicated more times. The most recent convos are not duplicated at all.
So I think when new comments are added, it should check if it already exists. Or it needs to not add comments before the last update.