SoftEther VPN User Forum

Softether tends to route internet requests through the vpn server.
You could try to set the metric on the vpn interface to automatic or a high value like 9999 to prevent that.

This is normal.

The VPN client will remove your original default route if there is a default gateway provided by the VPN Server.
Therefore, your wireless connection becomes limited.

The most important thing is you are able to access the internet after you connect to the VPN Server and can access the internet through your original internet connection after disconnecting the VPN.