Hey, seems that there are something wrong. You may need contact the tech support to check the warranty.

https://www.tp-link.com/en/support/contact-technical-support/#Hotline-Support

A bit of an update here: it looks like I was having a double NAT problem in my network caused by my provider's router (an Arris one), it looks like that was enough to bring down the second band for some reason.

Given that I cannot put the Arris one into bridge mode (you have to actually call the provider to do this :/ ), I've put the TP-Link one and reconfigured my network. It now looks like everything is fine.

But, now my TP-Link is just an expensive bridge. The first 5Ghz band and the second one have very different speeds (still getting around 100Mbps/40Mbps on band 1 and almost 500mbps/50mbps on the second one)

I'm not satisfied with this new network config given that I don't really have control over the Arris router, so I'll contact my provider next Friday so they put the router in bridge mode (and reconfigure my whole network again yay!)

pablitt wrote

A bit of an update here: it looks like I was having a double NAT problem in my network caused by my provider's router (an Arris one), it looks like that was enough to bring down the second band for some reason.

 

Given that I cannot put the Arris one into bridge mode (you have to actually call the provider to do this :/ ), I've put the TP-Link one and reconfigured my network. It now looks like everything is fine.

 

But, now my TP-Link is just an expensive bridge. The first 5Ghz band and the second one have very different speeds (still getting around 100Mbps/40Mbps on band 1 and almost 500mbps/50mbps on the second one)

 

I'm not satisfied with this new network config given that I don't really have control over the Arris router, so I'll contact my provider next Friday so they put the router in bridge mode (and reconfigure my whole network again yay!)

Oh, really. Maybe the double NAT affects the performance. What is the model number of the arris modem?

Back to your case, per you said, contact ISP to make the arris modem bridged and check whether it works. 

For the speed issue, have you ever tried to change some wifi settings? Like channel and channel width?

Yes, not only double NAT was affecting the performance, but it looks like this also brought down the second 5Ghz band (and for some reason only the second band).

It looks like the problem on the speed for the second band lies in the combination between the Channel Width and the Channel number. After testing different combinations, Width Auto and Channel 161 is giving me the proper speed (I got 492Mbps / 50Mbps).

I fear the same thing is happening to the first band, testing different combinations of channel width and number is giving me different speeds (I just got 337Mbps/50Mbps, which is quite the progress from the 100Mbps / 50Mbps I was getting before)

I’ll keep trying combinations, this area is very crowded in terms of wifi signals and the amount of channels is limited :) 

I'm definitely calling my ISP today, I don't like not being able to control my own network.

Thanks for your comments and suggestions!

haha, surely do.

@pablitt - I get similar problems with my Archer C3150 V2 - after 24hours or so, the speed of my 5Ghz band drops and then both bands stop accepting any new connections - The firmware is nearly 2 years old despite having only bought the router 4 months ago.  Overall I like the router, but it DESPERATELY needs a new firmware release to address some quite deep seated and fundamental issues.

I like TP Link products, but the on-going support is really poor

@Kevin_Z 

Hi - Thanks for the response:

Firmware is Archer C3150(EU)_V2_170927 and I am set for UK

Symptoms - I use TP Link range extenders and they lose connection to the 5Ghz signal after 48-72 hours.  I have positioned them carefully and after a reboot the range extenders say that the signal is good but over time the 2.4 band stays ok but 5Ghz drops out and won't reconnect.  Reboot the router and all is good.

In similar timeframes devices stop being able to connect, with IOS devices saying that the password is incorrect.

After a reboot and for around 24 hours my network is great, but I need to reboot twice a week.  I use all the standard settings for wireless

Thanks

@Kevin_Z 

So... Bought 4/8/2019 from Amazon UK

Range extenders

WA850RE V5 - Firmware Build 20181107

RE305 V1 - Firmware Build 20181026

RE450 V2 - Firmware Build 20171220

All up to date as far as I am aware - These all connect directly to the C3150, I don't daisy chain - the C3150 is in the heart of the house and the Range extenders are 'spokes'

I will try changing the settings as advised

Thanks for your help.

BTW - are there plans to upgrade any of these Firmware builds?  While I am happy to try and resolve the issue in config I would like to know that a proper solution is in the works