Wireguard - Internet access not possible


I’ve recently setup a wireguard server with pivpn (GitHub - pivpn/pivpn: The Simplest VPN installer, designed for Raspberry Pi). The installation worked well and I’ve also activated the port 51820 on my router. After connecting to the vpn, I don’t have access to the internet anymore. In seldom cases it works but with a long delay. On Android and Windows it’s working perfectly, but not in Linux.
I’ve also installed some additional components like networkmanager-wireguard or wireguard-modules and tried it with different kernels, but it doesn’t work.

If I try to connect to the vpn with sudo wg-quick up /path/to/vpn.conf, it shows the following error message:
Failed to set DNS configuration: Unit dbus-org.freedesktop.resolve1.service not found.

I haven’t edited the config files from the server and the client.

Thank you for your help in advance!

Same issue here, every time i change network/location, PIVPN/Wireguard on Manjaro, lost access internet, i have log into pi-hole, and then starts to work again, what coul it be?