Traefik 2 on Synology unable to connect to services on the host network

Traefik Traefik v2
,
3

i have it configured as followed:

http:
  routers:
    hass:
      entryPoints:
        - https
      service: service-hass
      rule: Host("hass.blahblah.nl")
      middlewares:
        - "hsts"
      tls: {}

  services:
    service-hass:
      loadBalancer:
        servers:
          - url: https://192.168.2.9:8123
        passHostHeader: true
        passTLSCert: true

i have used the following guide: