Not receiving notifications for WhatsApp calls

[vvaklnprm]

Hey guys,
I don't get notifications for WhatsApp calls sometimes. It's random and doesn't really follow a pattern.
I am guessing it happens when I don't open and use WhatsApp for a few hours.
Anyone else facing this issue and any ideas for fixes?

 

[ziddey]

settings>battery>battery optimization>whatsapp>don't optimize