Kindly enable the below-mentioned permission on your device once and also disable other app lock services on your device.
1: Open the Safehouse app > Click on the App Lock feature > Click on activate App Lock.
2: Allow permission to Safehouse Locked Screen over the apps that you choose to lock – click on Accept.
3: Allow permission to display over other apps.
4: Allow permission to track when the locked apps are open – click on Accept.
5: Permit usage access permission.
6: Then set and confirm your pin > Next set fingerprint and confirm.
7: Click on add apps > Then manually select the apps which you want to lock (lock your specific apps).