WhatsApp shows I'm on call when I'm not What reasons are there that WhatsApp shows me on another call, although I am neither using the application nor the phone as such. I don't know enough about WhatsApp to explain this to a friend who thinks I am lying. Could connection problems lead to a false status?
It's a software bug.  Try reinstalling the app and it should fix the issue.  Sometimes it's the network coverage as well. If the phone is between networks like connecting between Wi-Fi and cellular data it can do something like this.