Why won't my gallery sync to Facebook anymore?

i have used the sync gallery on my s4, i love that i can keep my pics elsewhere.

but since few weeks ago my photos have stopped syncing to FB, i have checked the setting ans they are all on to do this, i have uninstalled and reinstalled FB but has made no difference.

one thing i note is under my account manager setting with FB the sync gallery option has gone, only the sync contacts is there?

how can i get this back?

Please any help or suggestions. It was working just fine and a few weeks ago it stopped posting to my fb page.???