@Natalie123,
1Password might have a different approach for storing the user data - could be online, because of which the syncing occurs even if the app doesn't start.
But in the case of Enpass, the data is stored locally on the user's device. The cloud service is only used to sync the data. Since Enpass is an offline manager, this is a limitation here that you will always have to first unlock the app and then only the sync will start. This is one of the security features of Enpass that no other app or person can access the app data without the master password.
However, please note, the sync usually takes less than 2 seconds time and thus you will be able to use the updated passwords within no time.
In the below example, we have tried to make clearer why Enpass needs the app to be unlocked first to sync to the cloud.
Suppose you are using two different devices(D1 and D2) and they are synced via cloud.
You changed the master password for D1 and it got stored locally.
Whenever a change is made in the Enpass, the syncing starts.
Now on the device D2, whenever you open the app, it first checks for the local data.
It will need the older master password to unlock the Enpass app since the app isn't synced.
This is needed because of the security issue.
Once unlocked, the syncing starts and thus you will now need the new master password to unlock the app.