@Scoredo 

In my opinion it is totally unacceptable for TP-Link to continue selling the P9, given the well documented issues that many users are experiencing.

The concept is brilliant, but the execution is not.

My set-up does seem to work most of the time, but I do get dropped internet connections.

And sometimes, for no apparent reason, one of the Deco's gets "lost" from the network, even though it hasn't been moved or plugged into another mains outlet.

The one thing I want to be able to see and have more control over is which connection each Deco is using to communicate back to the main modem.

Right now, we have no idea if Powerline or Wi-Fi is being used for the backhaul and if it could be optimised by manual intervention rather than allowing the firmware to determine which route to select.  

@lohr500 absolutely. App is telling me almost nothing. Mine seems to be ok for most of the day, but I get drops later afternoon evening. I check and have no issue from main router. Just cannot get them to work without interruption so useless for work webex meetings or kids playing online games. Can't get support to even talk to me. I'm going to try Devolo Magic WiFi. It's a German company and also powerline mesh WiFi. 

@Scoredo 

Prior to buying (wasting my money?) the P9s I was using Devolo powerline plugs to extend both my wired and wifi network.

They worked faultlessly but weren't Mesh. Even though I set up the SSIDs on the Devolo wifi units to the same as my main router, we got breaks in connection as we moved around the house with portable devices.

That's why I decided to go down the TP-Link route so I could take advantage of the Mesh technology.

I need powerline as the walls in our house are very thick and wi-fi signals cannot make it through to all areas, even with extenders. 

Initially I purchased an MR600 router as I liked the idea of having a 4G back up.

The MR600 supports TP-Link Onemesh. Different technology to Deco Mesh but should have given seemless roaming through the houe.

But then I found out there was no ETA for the Onemesh enabled powerline extenders, so the MR600 was a waste of money. I ended up selling it on eBay two weeks after buying it, losing around $40 in the process 

Now it seems I have purchased another TP-Link product range that doesn't work as it should. 

As TP-Link are unable to give any firm commitment as to when improved firmware will be available, I am going to return my P9s to Amazon as defective.

The Devolo Magic 2 solution is worth a try I guess.  

@Scoredo 

I returned my P9s yesterday.

There seems to be a bug in, at least, Access Point mode, where the Deco reports the wrong Gateway server to some wirelesss clients and that makes them lose connectivity after a while. Restarting the main Deco was the only solution, but since that makes all the network go down, it makes unusable.

Funny, the only wired client that I had connected to the main Deco never exhibited any issues.

Given the apparent lack of support for these for almost one whole year, I just opted by returning while I still could.

I'm waiting on a pair of Devolo Magic 2 now, to see if they work. If not, I might give the P9s a second try, as concept wise they seem to be the ideal solution, but never before a new firmware shows up

@jpasan essentially the Magic 2 WiFi are the same thing. Powerline and mesh WiFi so definitely worth a go. I have one problem area that extenders/mesh won't reach so I may return my P9's and then but a single power line extended for that specific spot and Ethernet the two devices to the powerline, and then buy a normal (not TP-link) mesh system for the rest of the house. 
 

Support is woeful. Has another two hours this morning on an online chat and got nowhere. Can't believe they are still selling this in the state it's in. Surely some people must be getting it to work or they would have gone bust! 

@Scoredo Mine are now on the way back to Amazon.

Even if TP-Link improve the firmware/functionality of the P9's in the future, I wouldn't buy them out of principle. 

@Scoredo

Before returning my P9, I'll post my reply here. Maybe if the people from tp-link do their job and check these comments, they can figure out what is wrong.

Anyway. Installing went great. My original modem/router was put in bridge mode and I connected the main deco and two slaves pretty easily. The main deco was situated in the meter cupboard on the ground floor. The first slave on the first floor and the second slave on the second floor. For about a week things looked great. WiFi speed almost matched the ethernet/wired speed.

After about a week things started to change. First thing that happened was that the slave unit on the second floor lost connection. The led turned red. I than proceded to install that slave on the ground floor in the living room. That seemed to improve the connection. The led stayed white and WiFi and internet had no problems.

Than after another 4 or 5 days everyting took a turn for the worse. My devices stayed connected to WiFi but every ten to thirty minutes internet access disappeared. Only sollution as mentioned a lot seemed to be disconnecting from the WiFi and reconnecting. But the connection issues kept returning. I've changed the positions of the deco units. Cnhaged the ethernet cables between the main unit and the modem. Turned everything off and on. Reset everything. Last thing I did was to disconnect both slaves and use only the main deco.

Strangely enough, that was the solution to the internet connection issues. But of course having only one deco unit online as a router was not the reason I bought the P9 system. The mesh WiFi and powerline backhaul were the selling points. And now I can't use any of that.

So my two cents on this is that the problem seems to be in the slave units. Maybe competing for connection or some issue with the powerline backhaul preventing internet connections but allowing WiFi, but I'm not going to wait for a firmware update to solve any of these issues. If an upate comes at all. Tp-link isn't very clear about that.

Not sure if I'm going back to an other tp-link product. I think I'll check out some othet maunfacturers. But for now I would definitely not recommend anyone buying the P9 and wish I'd checked this forum sooner.

@RiskOz 

I think you are correct, it is something in slave units. Wish I could even see if powerline was working, backhaul, Smart DCHP was active. Just a mess. Such a shame.