When using Cloud all of your library, including shows is synced. I guess something is not working as expected then? Can you share what you expect to happen after signing into Cloud?
When I log in I would expect Trakt to be reflected on both my apps, and show the same watched and collected information.
At the moment I have a few shows on Trakt that are just not syncing and showing the same results on my devices.
Trakt shows seasons and episodes watched and collected, my devices show only some seasons and episodes as watched and collected.