If your device has a slow or unreliable internet connection, your database can take a long time to open. This is happening because Strongbox is trying to check for changes to your database but cannot complete this check.
If you're having issues opening your database because of an unreliable internet connection, you can choose to open it offline. This will open the most recent of the database that has been downloaded to your device.
To do this, long-press the database on iPhone/iPad or control click it on Mac, and then choose Open Offline.
Please note that if you have recently edited the database on another device, opening the database offline and then making changes could increase the chance of sync conflicts.