S8 not showing incoming calls / alarm screen when screen is locked

[Meyapan]

In my Samsung S8 running Android 9 with security patch 1-Jul-2019, it doesnt show up incoming call answer screen. Instead it prompts to input password with a button "Return to Call". This is very annoying prompt everytime to answer calls / dismiss alarms, calendar reminders. This is happening for quite few months. 

I have tried couple of solutions from Samsung US community. But doesnt work for me.  Please help.

Incoming call screen

[Mittuvichu]

Mmm, its a bit complicated.
Go to settings > apps > click on the three dot menu on the right top > special access >Appear on top and turn off all thirdparty apps. Restart your phone and try ringing your phone again. Check the screenshots attached. This is a screenshot from my Note 9. Some option may vary in your device.

[Meyapan]

I followed steps you mentioned with three below combinations in Appear on Top settings and did restart every time.

> First disabled only third party apps.

> Disabled all apps.

> Disabled most of system apps also except Call, Phone Services and UI.

Everytime i restarted, it worked (no unlock prompt) for 2 or 3 incoming calls with phone locked for every attempt. Then again unlock prompt is back during incoming call. 

Then I Reset App Preferences in Appear on Top. Now new problem: everytime i restart phone, during first incoming call phone screen lights up but Call is not displayed. 

[Mittuvichu · Accepted solution]

🥺🥺
Take a backup and reset the device. Use smart switch to backup. It will backup all app and data in the device.

[Meyapan]

ahh... how do i make sure the very same app or settings that triggers unlock prompt (during incoming call) does not happen when i restore from backup?

[Meyapan]

Thanks for helping. I reset the device and restored except Settings to be sure. Let me try installing caller ID app.