I got an iPhone X yesterday and went for a run last night. I shared photo with stats to Twitter fine, but when I went to send to FB the pop up comes up, but then disappears back to the photo with stats, and I can't post. I opened Connect on my previous phone, iPhone 7, and shared photo with stats to FB just fine. On my iPhone X, I logged out/back in to FB and Connect, deleted/reinstalled FB and Connect, and none of that helped. I finally talked to chat support today and was told that there are a few tickets open on this issue. It is indeed an issue with iPhone X and Connect being able to share photo with stats to FB (although maybe not everyone using an iPhone X is experiencing this problem?). Weblink shares fine. I was told, "There are not many customers experiencing this problem so it may be a little while until there is a resolution." Well gee, thanks haha. I just figured I'd post this in case others are experiencing this problem as well.
Maybe if you have time, talk to chat support, that will be one more ticket they will have to add to the issue, and if they get more and more complaints about it they will work harder and faster for a resolution haha. I mean in the end, it's not a huge deal, but I run in some scenic areas and I know I have a few FB friends who like to see my photo that I share. If I'm able to keep posting from my iPhone 7, although an annoyance, I suppose I'll continue to do that until there is a fix.