Routing to internal network doesn't work

Hi,

 

i set up a PPTP VPN by following this guide: https://community.sophos.com/kb/en-us/116036

The VPN connection works. However, i can't reach the local network, neither via RDP, ping or whatever.

A traceroute from an internal server to the vpn client stops at the gateway. Same happens from the client.

The firewall log shows that the rule is executed (green, when trying from both sites) but it doesn't seem to get through.

I also deactivated the local firewall but the issue is still the same.

 

Any ideas?