When you open Infuse from the background, go directly to the Settings > Library, what do you see on the left hand side of the screen under the Movies, TV Episodes, Other stats for "Last Updated? What do you see after the “Sync with iCloud (last:…)” on the right hand side of that same page?
It seems the automatic updating works a lot better after a while when on. Last night I checked a few times from background and it kept it updated. So the problem seem to be first time from fresh boot of the ATV and directly to the infuse app. Like my example yesterday when it was 22h behind.
How long is normal for the app to trigger the update and is it depending on what protocol is running?
For me Infuse seems to do a complete scan and sync every time I bring Infuse to the front as long as it’s been a couple of hours since the last sync. I think that Infuse will do a scan and sync every couple of hours of active use or when it’s brought to the front after being in the background for more than a few hours. If you fully quit Infuse and then restart the app it seems to do the full sync then also.
One thing that may be affecting you is a possible problem I brought up in another thread you may want to follow.