@Alfon0904 I called my internet provider, they said something was wrong with my net Filter or something. Then it got fixed without any visit at my home

@Kevin_Z Good day, Problem is already solved, the router was the cause of this problem. but thank you.

So i had the tp-link TL-WN823N for a half year now, but since yesterday i can only connect with the wifi but have no internet connnection. I tried erverything, restarted the router, plug the adapter...