I'm sorry for any inconvenience. I was talking to Shane about this ticket to see what we can do.
And we found that this needs deeper investigation.
If you don't mind, Share will reopen the ticket and will work on it again and I'm sure that he will do his best to fix the issue if it's from our side.
I think I found the cause for the FB issue. I've used the FB debugger and the problem is related with the slug issue and also the scheduled posts. It seems FB it's not able to scrap the posts correctly if these are scheduled . I've scrapped them individually and it now sees it all correctly (apart from the broken ones).
See here: hidden link
I think because we have been changing the slug to try to answer the other issue this is confusing FB somehow. So, when the slug issue is solved this FB issue will also be fine.
In the meantime I opened another ticket to solve the slug/category issue as I think this a side issue and I can assume it is solved (for now).