Black screen issue when receiving a call from WhatsApp

[HeSo]

Hello

When I resieve a call from whatsapp the screen is black and I have to unlock the phone to see who is calling

[LongHiker]

@HeSo You can check to see if it is enabled properly.

1. Open phone settings
2. Click on Notifications
3. Click on Lock screen notifications
4. Ensure that Show content is enabled and then click the gear to the right of that setting. 
5. Ensure that WhatsApp is enabled in the list. 

[HeSo]

I did that, but it is still the same