I am a bit confused by what you say. You say "am having problems to sync some catalogs" but you do understand that you can only sync a single catalogue? Your problem might be explained by opening a second catalogue, one that isn't the synced catalogue. But there's no such things as "smart catalogs". So have you written "catalogs" when you meant "collections"?
From Help > System Info, what's the first line in the box scrolling box? Does it read "Lightroom version: CC 2015.6.1"?
In Edit > Preferences > Lightroom Mobile, what is shown under Status?
Show the top panel (F5) and click the Identity Plate. What's the first line - Sync with Lr Mobile? Is it paused?