I have both the iOS app and the Mac app, both through the app store syncing over iCloud. I've noticed that I have about 7 logins that are in the Mac app but do not appear in the iOS app. When I check the preferences of the Mac App, it says it last synced a few minutes ago, and then I manually start a sync in the iOS app. However, even then the iOS app does not gain the missing logins.
1Password Version: 6.4.2 (iOS), 6.3.1 (Mac)
Extension Version: 4.5.6
OS Version: 10.11.5
Sync Type: iCloud