@childsplay 

I would try several things to try and locate the problem. First, I would set up different wireless SSIDs for the 2.4 GHz and 5 GHz WiFi bands (you will have to turn off Smart Connect if it is enabled). Check to see if you can connect to each SSID which would pinpoint the problem to a particular band. If you can not connect to either SSID, then I would delete the existing connection(s) in the TV, unplug (not just turn off) the TV for half a minute or so (this should cause the TVs cache to be cleared), again plug in the TV, and set up a new connection. The last thing I would try is to reset the TV to factory defaults and again set up the connection.

  @jra11500 

I did al those things before i noticed my firmware was updated (it updates automatic at night)

With the exception of disabling smart connect as my guest network is set to 24GhZ so I tried to use my guest network.

The results are the same on both bands. The TV is never seen in the client list even as it does gets a ip and the connection with the accesspoint is made.
I can ping my TV from my lan.

But all the time the TV has no internet connection.

  @childsplay 

I'm assuming the IP address that the TV receives is an address within your LAN's IP range and not an address that starts with 169. I'm also assuming that when you say "accesspoint", you are referring to your router. If that is true, then you will probably receive a response in this thread from Tp-Link in a few days as they are now on holiday (Sping Festival) until early next week.

It is probably unrelated but I have seen a similar issue in the past. A Samsung TV always attempts to contact one of its own sites to confirm the internet connection. When the DNS query for the site is blocked by a DNS blocker site, the TV shows a connection to the router but not to the internet. When that happens, it doesn't even try to establish a connection to a different site, such as Netflix. Since you tried a different DNS (8.8.8.8), your issue most assuredly is caused by the router firmware.