@Andy_Ho @Tppp 

I was also facing issues with Deco P9, and it seems that all issues have to do with the WiFi backhaul.

I was able to solve my issue by disabling the WiFi backhaul. Check my post below.

https://community.tp-link.com/en/home/forum/topic/175006?replyId=435492

@LeonardodaVenci I returned the product.  Neither the product or the software are ready for public sales and I am surprised that you guys would sell this model knowing that it is not complete.    Sure leaves a bad taste for future TP Link purchases ...  at least in my mouth. I will be hard pressed to support any TP Link purchase personally or professionally. 

@LeonardodaVenci 

Seems to be a lot of lip service WRT the firmware update that will be capable of monitoring the powerline connection.  I just purchased the P9 and continue to get 1  of the 3 units dropping out of the network and it does not appear to me that the powerline backhaul feature is working. Like others in the thread, this was a driver in buying this unit. Think these will be returned to Amazon with a negative review.

@Applecart 

It has been almost a year with absolutely no hint of resolution.

I had to return mine.   Just too many things not working properly.  I do not even see how it was sold like this.

I believe these were conducted as free expiriments to find out what things worked and what did not, as well as how far they could go without backlash.

Sooooo very much potential.   Such a waste.

Tom

@LeonardodaVenci - I agree !!!
 

6 (MORE) months later... - and still nothing from TP-LINK :-/ ???

I too (recently) bought the P9 due to the Powerline backhaul... - but I'm NOT impressed/convinced if it even works...

Often I see a burst in the speed; where it (fast...) drops to almost no througput. Video streaming etc. is a No Go in these cases... :-(

I need/look forward to the firmware update, that can TEST THE SPEED of the current availabe different backhaul channels (wifi, power line, ethernet) in each P9 - and:

A) Automatic change/select the (current) best method !!! 
B) SHOW the results of such (prommised) speedtests... ???

PS: And the AP's shoudl have the clients "go for" the 5GHz channels (faster), when ever there is even fairly high signal strength !!!

@Kevin_Z  
WAKE UP, TP-LINK ???
We payed almost the double price for the P9's over the M5's... - Give us some value for the money? ;-)

@Torben.H 

They lost my business forever.

I will never buy another TP Link product in my life.

Products may (ot may not - who knows - certainty not the end user) be functioning, but the customer service is the worst in the business.   I have had DLink Lynksys Asus Dell and TRENDnet routers in the past and currently have a Netgear.  I have NEVER seen a forum thread this important be ignored for so long.

I can only thank my lucky stars that I was able to talk Amazon into allowing a return at 47 days.

Then bought the cheaper Netgear Orbi RBK43 system.  What a difference!!  Especially considering it only uses a 5gHZ backhaul channel AND it is AC2200.   It is still faster and I have no connection issues (especially the 2.4gHZ devices - like cameras) and no dropped devices (Current uptime 74d13h44m).

I feel for you guys.......really I do.