TP Link Deco X50 - No Server ping response after 1 second

[posmykmedia]

I use OpenMPTCProuter to combine the internet connections via fiber optic, 5G (Telekom) and Starlink. (Aggregation).

I use a Firewall Micro PC with 8 GB DDR4 RAM, 256 GB storage and 4 2.5gbs Ethernet ports (https://www.amazon.de/gp/product/B0BMVFGQSF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)

As software I use ext4 image (EFI): openmptcprouter-v0.60-6.1-r0+24843-acf40c022e-x86-64-generic-ext4-combined-efi.img.gz (2024/04/09).

As a server I use Debian 12 on an Ionos server.

The 5G router is a TP Link Deco X50, 5G router with 2.5 Gigabit port (https://www.amazon.de/gp/product/B0BWS5WBQ7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1).

The problem is that when I connect this router to the OpenMPTCProuter, I get the following error message:

No Server ping response after 1 second

But there is an internet connection, because direct access to the router gives me an internet connection.

What am I doing wrong? What exactly do I have to do? The 5G router also offers DHCP as normal.

This is what the internet connection settings look like:

Please provide some tips.