Hi @Mago. No, unfortunetely. Well, kind of...I connected the TV via ethernet cable and I've been using it like that. I read somewhere that deactivating Fast Roaming on the deco works. That seemed to solve the problem but then again...you miss the fast roaming option which is useful. 

This is the last email I got from TP-LINK support, which btw is great. They did several remote sessions to capture packages and made me try a few custom firmwares but they didn't hit the nail in the head. However, I have given up since I plugged it in.

Email from TPLINK Support in China: "Turning off Fast roaming actually simplifies some of the wireless interaction processes. For this problem, it may be that when the device and Deco use the default interaction mode, some packets are not processed by the device, and the same packets can be processed after turning off the fast roaming, thus turn off fast roaming solved the problem."

Thanks for bringing this up again, I will contact them again see if they have any news. 

@than.bimp thanks but this is still not a solution, it's a workaround really...