Ensure all traffic is sent via VPN tunnel

[Iamnotarobot]

Hello Folks,
I am new to OPNsense and I have a rather simple question. Following the documentation I did setup a WireGuard VPN Tunnel to ProtonVPN on my appliance (latest FW installed). Watching the WireGuard status page I see traffic being send and received. How can I ensure no traffic going towards the internet is bypassing the VPN tunnel? 

I have setup two NAT rules outgoing, one for IPv4 and one for IPv6. Both are set us the interface regarded to the WG Instance, the local subnet range as source.

How can I ensure no traffic going towards the internet is bypassing the VPN tunnel?   ...or if some packets are evtly dropped.
Under Reporting/Traffic I can see traffic related to the WG interface but also traffic to WAN, which is a bit confusing. Please see screenshot attached.

Thanks for the help!
BR, Hans