Ähm...Die IPs vom Tunnel liegen im Subnetz vom LAN... Du musst für WG ein eigenens Subnetz verwenden!
Ich würde auf jeden Fall erstmal ein anderes Subnet nehmen um weiter zu testen.
The tunnel address must be in CIDR notation and must be a unique IP and subnet for your network, such as if it was on a physically different routed interface. The subnet should be an appropriate size that includes all the client peers that will use the tunnel. For IPv4 it should be a private (RFC1918) address, for example 10.10.10.1/24. For IPv6, it could either be a unique ULA /64 address, or a unique GUA /64 address derived from your prefix delegation. Do not use a tunnel address that is a /32 (IPv4) or a /128 (IPv6)