@David-TP 

I didn't mention it but my deco works in AP mode, fast roaming was set to off, I can't find beamforming option in  Deco APP>More>Advanced.

What is interesting: today for test purprose I add my old  TL-WA850RE to mesh and daikin is connecting to it's network.

Grzegorz

I just got a new BRP069A78 WLAN unit and I can confirm that it cannot connect to my TP-Link Omada network with EAP615-WALL AX1800 Access Point. I have created a 2.4Ghz only network and still was not successful.

The unit connects just fine to the WLAN of my home router.

Please help

  @GPGP 

Did anyone sort this?

I have the same problem with a TP-Link RE550.

Won't connect with WPS to my Daikin heat pump.

Direct to my Draytek router works fine.

  @GPGP 

Hello,
I recently bought a Daikin Atherma 3. Having a problem connecting the WLAN adapter to our internet connection. I connected to the portable router without any problems, but with 5G stationary router we having problems, had to split the connection into 5Ghz and 2.4Ghz - I tried to connected to 2.4Ghz because it was stated that only this connection is acceptable. I have tried almost all the 2.4Ghz settings and they are currently as follows:
Network Mode - 802.11 b/g/n
Channel Bandwidth - 20Mhz (also tried with 20Mhz/40Mhz)
Frequency (Channel) - 2437Mhz (Channel 6) (also tried with channel 1 and auto (channe1-11))

Thanks for any help!

  @AlexDone Nvm, just changed security mode to WPA/WPA2.

  @GPGP I have the same issue as described above. I cannot get the TP Link M4 connected with my Daikin system through the ONECTA application. I have tried connecting with the orginal wifi (without having the Deco M4 in between) and that worked fine. I have tried various options within the Deco app; turning off fast roaming, changing the frequency to only 2,4GHz but all without the desired outcome. Any help is appreciated

  @JasperNL 

I didn' t find any solution except using another cheap access point. I asked Daikin Europe NV  by their contact form but no answer at all... Authorized serviceman from some Daikin representative  confirmed me that this problem is very common but he also have no solution so far. 

  @GPGP thanks for your reply. Having an additional accespoint really defeats the purpose of having the tp link m4 WiFi mesh set up if you ask me.. @David-TP Can you please provide some feedback?