number-of-pending-notifications indicators stuck on icons on home screen

[halfbeing]

On my home screen on my LG G5 the counters for the number of pending notifications for two of my apps are stuck. I'm talking about the red circle with a number in it that appears at the top right of the icon for an app when you have new messages. In my case they are stuck for Whatsapp and Quora. I've tried rebooting the phone, and I've tried messing around with the apps in question, but I just can't clear these notifications. What should I do?