Can you post the screenshot from AX600 above in normal /day to day/ use - non link aggregation ? Or at least I have to know wheather you are receiving a public IP address on your WAN/Internet...

@Tod @Kevin_Z Have you tried to delete the saved wireless network T-Network-Car and add it again ?

@aothelal Have you hard reset the router to see if anything changes ? Is the returning the device an option ? The other thing you could do is to contact the local support an ask for help.

@OlafKroezen Check that thread.

From an official store or from a person ?

Are you sure that's the latest FW ? On your car still shows the encryption as WPA-PSK TKIP. If it's the latest FW, try to reset the device and reconfigure.