Ignition 8.1 not listening on ip v4 port 8088 on fresh install

You could try adding -Djava.net.preferIPv4Stack=true to the additional parameters section.

It’s binding to IPv6 fine:

Dual IPv4/IPv6 is supposed to be automatic, not sure why you’re seeing an issue. Must be something about Deb 10.

Can you not access the gateway at localhost:8088 or 127.0.0.1:8088?