EX3301-T0 Isolating LAN ports from each other

LD0035

Hello,

For security reasons I want to separate a home hosted webserver from the rest of my home network, but none of the settings seem to work for this.

The server sits on a separate LAN port, and Interface grouping creates a different network, but the router keeps routing between them and I cannot find a setting to turn it off. VLAN groups don't work either, neither is it possible to configure the firewall to block traffic between the two networks. Did I miss something or is it impossible to disable this behavior on this router? Router is provided by the ISP.

Any help is appreciated!