UPDATE to my case.

Tp-Link tecnical support answered just saying (and ignoring what I've said):

Dear client,

    Since your Deco works normally with other devices, it's probably some TV's specifc configuration, because Fast Roaming cannot comunicate with ancient devices if activated, verify if you TV is copatible with IEEE 802.11r standard. 

Really, it's better notanswer at all than answering things like that (not saying that the answer came with some typo errors). 

Can't TP-Link do better ???

@alexantao 802.11r is even not part of the specs of the Deco M9 AP on their website (https://www.tp-link.com/us/home-networking/deco/deco-m9-plus/#specifications) but IEEE 802.11 ac/n/a for 5 GHz and IEEE 802.11 b/g/n for 2.4 GHz are and are also supported by TVs...

What I did to get my TV in the network not pulling a cable from the router to the TV was to install a powerline adapter close to the TV. It works pretty well and offers decent bandwith.

Hi guys,

There are many replies on this thread and I quickly looked through the answers. However, I haven’t noticed any solutions provided to the problem. The thing is a have the same issue right now and it drives me nuts.

@Victor8ST 

I dont know what to say, probably Android Tv are not compaible with wifi mesh architecture

Yes, it must not be. But The protocol should at least permit connect devices that do not support this configuration. Or... why there's an option o DECO's App that disables it, if it does not work ? All my devices at home connects perfectly, only this AndroidTV.

Anyway, according to the article somebody posted before in this same topic, this Fast Roaming has no effect on Personal WPA, but its more related to Enterprise WPA. So, I forgot this cofniguration for a while. When DECO's FW or my TV's FW gets updated I'll try again.

Regards...

@ScreenNameNL 

Hi all,

I have just bought 2 of the M9 plus and ive tried everything and it wont connect to my panasonic TV. The other one is fine, just this one it does not - and I use this a LOT for smart TV feautures and now I cant' use it.

Eveything else seems fine...just this one TV.

There was no update to the systems from the app, with this is mind...its making me wonder if TP-Link are updating these systems.....Eero are doing regular updates and woring on public requests if any devices are not working......so i might jump ship while im messing around with it all.

Ade

@Adie-H 

Hi Ade,

Have I understood correctly that you have another TV which does connect successfully with fast roaming enabled? 

If so, what OS/version does it run on? 

@Smercius 

Hi,

Thanks for the reply.

Yes, I have another panasonic TV in another bedroom, this connects all ok - just the one in the master bedroom does not connect at all. I have sent a photo of what comes up - says the IP is not set.

I have done a live chat with TP-Link but was getting an answer/post every 20 mins and took 1hr to get told to do 4 things!

Fast roaming is disabled (was by default)

@Victor8ST 

ok, Thailand TP Link support is great actually.

some android TV work well, some are not! 
 

Ok, my android Panasonic works well with Deco M9 Plus. However, Sony 2018 version and Toshiba old version don't know the model, both of them won't connect with the Deco!

SOLUTION! 
given by the Thai support team:

1st Approach:

Use cable, it solves everything 

2nd Approach:

before trying this approach, you should try this first by remove the WiFi password off, and try to connect the tv first, if it works, try below instruction. 
 

I don't like it though, he said some TVs don't support WPA2 security, since the Deco is "very secure," hence you need to ...

  --> turn on guest network name it as you want to appear to everyone in your house to connect 

  --> set the password for for you guest Wi-Fi 

  --> go to you main Wi-Fi, delete your password

  --> click at the WiFi name, and turn the "Hide this network from the WiFi list" on

 --> then! Go to your tv, use search Wi-Fi network by manually type the name of the main Wi-Fi that you just hid it from the WiFi list

  --> then connect! 
 

hooray, it should work.

let me know if this helps...

@ThePiston Really not good solution, even hidden it's very, very easy to discover a Wi-Fi network. Any scanner will do that. Then your Wi-Fi is open for the world...