Problems with HAproxy reverse

[fuma-afk]

Hi,
I'm having trouble to reach the webgui outside my homelab using haproxy configured on my pfsense.

I have multiple services configured and all works (both ssl and not get correctly redirected to the https frontend with certificate offloading and i'm able to reach them from outside).

I can reach the webgui from inside my lab just fine.

I have the following configuration:

Webgui it's running on it's own docker container, with lan address_ 192.168.155.20:9290, the "script_name" field in the yaml has been commented so the page can be reached directly on ip+port

Backend config:
name: "hsweb", "address+port: 192.168.155.20:9290", "encrypt no", "ssl checks no"

no further configuration

Frontend ACL config:
"hsweb", "hsweb.mydomain.xxx"

Action:
"use backend: hsweb", "condition acl name: hsweb"

provided i might be doing something incredibly stoopid, i tried to search issues regarding haproxy and found none and the main github page states to ask here if a reverse proxy doesn't work

Can anyone confirm it is working out of the box or some extra steps are needed?