@Martin6 I wonder if it's the same issue as this https://community.tp-link.com/en/home/forum/topic/610798 

It was found that they needed a hard reset with the reset button would get the powerline working maybe a factory flashing error.

"

1. Deleted my entire network in the app.

2. Swapped the decos around and started with a different one as the main unit.

3. Setup main unit from scratch after using reset pin in the back and set the network up again.

4. Plugged in first satellite and again used the reset pin.

5. Confirmed that showed the powerline symbol.

6. Repeated with the other satellite."

Thanks  @Alexmesh , apreciate quick response ...

What a disapointment!

Frankly, I don't have time to play around with units (reset the network etc...) - I expected that this thing works as advertised, otherwise I would have bougt different unit/vendor - I bought this model because of the powerline.

Thanks  @Alexmesh, 

Do you know by a chance if they are working on solving this (is it acknowledged bug, something they have on their roadmap to fix soon)?

If it's a dead end, then I'm thinking about returning this and buying something different...

  @Martin6 There's been a thread about this since 2019 https://community.tp-link.com/en/home/forum/topic/163064 they promised all kinds of things in future updates but are yet to deliver to this day. If it wasn't for wifi 6 and g.hn powerline backhaul I would of returned and gone for another product but there arn't any, they just string people along with hopes of firmware updates to add features people have been requesting for years so the return window ends and people are stuck with their kit.