Internet connection crash only when playing Overwatch

It seems like Overwatch is causing my whole network to collapse and force me to restart the router to restore the internet connection. This always happens in game about twice a week. I can play any other game just fine forever.
ISP assigned me a static IP address and I have a FritzBox 7430 router (brand new) wired to the gaming PC to whom all network traffic is prioritized to.
Windows firewall inbound rules are fine, network drivers up to date.
Right now I am not playing Overwatch because I don’t want other people to loose games because of my problem, I don’t mind loosing my own SR, I am bad anyway :wink:

This generally points to an issue with the network configuration, but is not a function of the game itself. Blizzard has some tips here that may point you in the right direction: