Why do I have a lock screen on my dial screen?

[Android Central Question]

S7 phone. Recently my dial screen locks after making or receiving a call. It says "Tap 2 Times to Unlock Screen. I can't even hang up without unlocking.

 

[B. Diddy]

Welcome to Android Central! Did you turn off the proximity sensor? https://gettechmedia.com/how-to-turn-proximity-sensor-on-off-samsung-galaxy-s7-s7-edge/. If you turn off the proximity sensor, it will enable that lockscreen. The reason is to prevent your face from accidentally pressing onscreen buttons while the phone is up to your ear.