Whatsapp Badge Disappears When Reading One Message But Other Chats Unread

Is there a way to keep the Whatsapp badge showing on the Whatsapp icon on an iphone when you've opened messages from one chat but there are still messages unread from other chats? It probably doesn't matter to most people but I'll go into Whatsapp and read one message and plan to get back to the rest when I get a chance but I then forget because the Whatsapp icon no longer shows the badge (and I have the memory of a goldfish). It's only when I open Whatsapp that I realise I've forgotten to respond to the other chats because you can then see a badge in "Chats" within the app. I've never had an iphone before but this wasn't an issue with my previous android phones. Cheers.