Network and/or Topology confusion

Hi all

i think i have some confusion about how to manage my networking through IPFire topologies.
This is the network diagram of my infrastructure, where the RED network is between IPFire and my Fritzbox and the GREEN network is instead all that is downstream of the IPFire (and therefore attested, as a gateway, to the GSM5212 switch)

I have no particular problems to date, except the following:

  • access denied when I try to access ipfire cache manager from my pc
  • some iphone apps (eg .: nest thermostat) won’t connect to my internal devices when i’m under ipfire proxy (tcp 800 or 3128)

i have my own Microsoft DHCP server, so IPFire running services are:

  • DNS Proxy (dns servers are and dns forwarding to my Microsoft DNS, dns forwarder is my pi-hole and my Microsoft DNS)
  • NTP Server (but some devices works with their predefined and not customizable ntp server)
  • Web Proxy & URL Filter (not all devices can be proxed)

is there something wrong?