@Dipal 

Hi, could you please refer to this link to help me submit the Deco APP log here:

How to submit Deco APP log

I ran into this issue before but it was restored automatically later. Apart from the error message in Network Optimization, I noticed you mentioned that "the network has been running extremely bad, although my broadband connection & speed has been fine". Can I have more details, like devices randomly dropping out or the websites being too slow to load?

Thank you very much and wait for your reply.

  @Dipal @David-TP I've been having this issue since the last firmware update to my 3 Deco M5s. But when I tap "Detection Failed. Please try again." it then appears to scan again, for only 1 to 1.5 seconds, and returns the result that both channels are optimal and reports the 5GHz channel to be Channel "0". As reported by the clients, It's actually using 5GHz channel 44, and will never ever stray from that despite reboots nor changing its 2.4GHz channel.

I contacted support who eventually funneled me to the RMA department who rejected my request because it's been more than 90 days since purchase.

Pretty disappointed.

  @AlarmingMelon 

Hi, thanks for the feedback.

I checked the ticket record. I am sorry that I could not help with the warranty policy.

I noticed you bought from eBay TP-link US official. The warranty from the US warranty office then, is 90 days for the refurbished product.  But eBay provides a 2-year Allstate warranty for its official certified refurbished partners. I think you could consider proceeding with the warranty service from eBay directly.

https://pages.ebay.com/refurbishedprogramwarranty/index.html

Thank you very much and best regards.

  @David-TP Thank you for the advice. While I have you, may I ask if there's any way to backup the Decos' configuration?

From what I see in the app and found searching these forums, it appears there's not, but double-checking. If not, hopefully that's a feature that could come in future firmware, as it's been a relatively standard feature of other router products and would certainly be convenient to customers who set up separate ioT networks, QoS preferences, and client connection preferences. 

EDIT: Second question, I actually purchased 1 unit via eBay as the seller, the other 2 Deco units were purchased from Amazon, also "renewed", approximately 1 year ago. Would they be subject to the same 90 day window, and does Amazon cover them any longer? If not, unfortunately all 3 units are past 90 days.

  @AlarmingMelon 

Hi, recently, there has been a new round of features under evaluation and I do see it is planned to support network backup on Deco.

But as usual, there is no ETA for it.

As for the warranty period for Amazon renewed devices, I think it is 90 days as well which should be mentioned in the product link and you could have a further check. But I am not sure if Amazon has any extended warranty.

The good thing about Deco is that each Deco could be set as the main unit and the network configuration will be saved as long as the main unit is online. In other words, if you get a replaced or new Deco later and add it to the previous mesh, it starts working as a satellite Mesh, and after switching to the main Deco, it would also get a copy of the current network configuration from the original main Deco so that the settings of separate ioT networks, QoS preferences would not be lost. However, the client connection preference needs to be reconfigured.

It also needs to be mentioned that if you haven't tried to switch to a different Deco as the main Deco in the previous troubleshooting, it's also worth a try.

How to Set up the Satellite Deco or a new Deco to be the Main Deco

Thank you very much and best regards.