Weird Network (Ethernet) Problem

[Techno993]

Hey guys,

 

i just finished building my new pc and encountered a weird problem:

 

When my Bandwith is fully used (e.g. downloading a game on steam), nothing else will load. I can't even google stuff or open any other websites. Google Chrome says the DNS-Adress and Server IP couldn't be found. Some times even the download on steam will stop. When running the Microsoft diagnostics it says there are connectivity issues with the broadband modem: Network gateway can be accessed, but no network traffic can be received from internet. The recommended solution is restarting the modem. But when i restart my router, the problem persists.

 

The Problem isn't the Network chip (Installed a new network card with different chipset today, same problem). I'm using Win11, all drivers are up to date.

Mainboard is ASUS ROG Strix B550-A Gaming with the Intel I225-V Rev3 Network Chip. My new UGREEN network card has the Realtek PCIe GbE Family Controller Chipset. Router is a Telekom Speedport 3 with up to date firmware. I'm only using ethernet, no WiFi available.

 

Thx for your help in advance