Hi! Callfilter.app is a spam call blocking app — it can’t make your phone “private” or control other apps on your device.
If you suspect your phone may be compromised, the safest approach is a clean reset:
Back up only important files (photos/contacts) to your Google account. Avoid restoring apps/settings from a backup.
Factory reset the phone (Settings → System → Reset options → Erase all data / Factory data reset).
After the reset, install only the minimum apps you really need, only from Google Play. Keep “Install unknown apps” / APK installs turned off, even if someone asks you to install something.
Update Android and Google Play system updates, and enable Google Play Protect.
From a different trusted device, change your Google password and important account passwords, and enable 2-step verification (2FA).
Check and remove anything you don’t recognize: device admin apps, Accessibility services, VPN profiles, “unknown” apps with special permissions.
If the same problem continues even after a clean reset, it may be an account/carrier issue (e.g., SIM-related) — in that case, please contact your carrier or the phone manufacturer for help.