If you decided to stop using Opal, you probably removed Screen Time Permissions or uninstalled the Opal app. Occasionally, Screen Time settings can still apply to your device, which means some apps may still be blocked. If this is the case, you need to Hard Reset Screen Time settings using the Opal app.
Here are the steps to follow:
With this, Opal will try to reboot your Screen Time settings from scratch. Once is this done, make sure you're not in any session, and open any app you want to test.
You Screen Time settings are now reset! You can uninstall the Opal app at this point.