L2TP IPSEC Clients can connect to the internal network but not to the internet

Hey everyone,

I thoroughly followed the guide https://www.sophos.com/en-us/medialibrary/PDFs/documentation/utm90_Remote_Access_Via_L2TP_geng.pdf with my test setup of a SOPHOS UTM 9 essentials firewall edition.

I managed to get my client connecting with no problem to the internal network - I am very happy, half the work is done. Unfortunately the client cannot connect to the internet through the VPN connection. Ping is possible to the whole internal network and also to the external WAN-IP of my UTM, but from there on everything seems to be blocked. DNS is also not working.

I setup the firewall and NAT rules accordingly to the guide, checked several times, no luck. It stays like this. With the "essentials firewall edition" the "advanced" section of the remote access is not editable, but this should not ne the cause on my opinion.

So the question is: is this guide still up to date or does this setup not work with the essential version of the UTM?

Thanks so much in advance!