Sophos XG v18 - PXE IP Problem

Hello,

i'm using an Sophos XG 86w Firewall.

i need to setup an PXE Server connection.

What i've done:

1. Set DHCP Options 66 and 67 in Console as admin

2. Created Firewall Rule to forward Port 69 from Firewall to PXE Server

My Infos:

- Firewall IP: 172.20.10.1

- PXE Server IP: 172.20.10.205

- Firewall Version: SFOS 18.0.3 MR-3

If i boot my machine to PXE it gets an IP Adress from Sophos DHCP but finds "172.20.10.1" (the Sophos) as PXE Server and gets Timeout. (See Image attached)

What mistake i have done?

Thanks!