How to protect whatsapp from others can reply incoming call

[Mangkudun Sati]

I use a lock password and fingerprint to unlock apps and if someone whatsappcall me I can unlock by my fingerprint but if the phone screen is off and I touch the power button then whatsapp is unlock and no need fingerprint or password and anyone can reply an incoming call
before never happened like this,allways asked to unlock when a call come in and touch power button
what can be happened?
yesterday I just updated software?maybe has to do with it?
I uninstalled and installed again whatsapp but same
Thanks all for help