Hi @Kevin_Z 

I still have the problem even with the new firmware.

@sca 

ok Tp link they will not answer you bcz they know all TPlink prodect will give you half  speed .

soluotion , you need to update  the  Firmware  agan . 

very important : 1- you should not  use any kind or  router futer  only setting wairless name and password .

                          2- Tern off anti virus  at all .

                           switch of  on if the speed drop after 3 dayes insted of 1 hours

For me i will go for other company

Bye bye Tp link for ever .

Apparently it's time to sell this device and choose a new one and definitely not TP-LINK company. I will never purchase your company products again! I can’t understand one thing - why is this attitude towards users? Is it really difficult to keep them up to date so that they do not feel simply deceived? Information zero - released beta and all. Without even removing the problematic firmware from the sites. Are they working on corrections or not, when is it due to wait? So far, only some questions to company representatives, but no answers! Nowadays, this is not done and is not done to people who support the company with their money, buying obviously raw products!

@mrmcg For me what worked was, set QoS speed manually to 999mbps and leave QoS on standard. I was able to get full speed after that. What can happen is the in router speed test isn't fast enough to get the full Gigabit speed, and then on QoS it does all the QoS based on the in router speed test. So you need to manually change it to 999 mbps. That fixed it for me.

@Kevin_Z Is there any new information when a new firmware for the device appears (not a beta version)? Release the beta version as the main firmware, since it is not convenient to use the web interface on beta (everything is in beta inscriptions). I personally have no complaints about the fixed beta version. I will be grateful for the answer!

I have this very same issue. I own an ArcherC5400 v2.0 and my firmware version is 1.2.5 Build 20191204 rel.63911(4555), the newest beta version. All cables are CAT6, installed less than a week ago.

When the router is used normally, my wired local network connections are limited to ~400 Mbps. The wifi speed is limited to ~100 Mbps on 5 GHz wifi. NAT boost is on and QoS is set to Standard. No changing of these settings makes any difference.

When I put my internet provider's router back and set the ArcherC5400 to access point mode, then wired local network connections achieve ~800 Mbps, and 5 GHz wifi achieves ~200 Mbps. So, the speed is doubled when the router is not acting as a router.

This is almost certainly a QoS issue. The big problem is, we can't disable QoS on our routers. Another big problem is, the firmware updates are non-existant.

I own quite a few TP-Link products (MR600, Archer C7, four switches and a few range extenders), and I am very dissapointed with the support we are getting as home users. All these products have obvious problems that could easily be fixed in firmware and yet they are somehow not.

@Kevin_Z Please provide an ETA for new firmware. Also, please advise your technicians to offer the option to disable QoS.

@Kevin_Z I just upgraded my internet to gigabit and am experiencing this same issue when I connect up directly to my modem I get 900+ on download but when going thru my c5400 v2 running firmware 1.2.5 Build 20190411 rel.52981(5553) I only see maybe 400 at most for download any ideas or suggestions?

@MikeD_PA 

Make sure you have rebooted the modem and, after it has rebooted, then reboot the router.  Also, I found that turning off QOS and statistics in the router's settings, and turning on NAT boost helped me.  Good luck.

Well I managed to get a stable 500 - 550 connection while using the c5400 v2 router but that is only about half of the 970 + that I get if directly connected to the modem. 

Sure would be nice if they would provide a fixed firmware update.  Otherwise may need to be replacing and finding a different router vendor to go with that offers true gigabit at the wan port.  

Thanks,

Mike

Apparently, the company stopped supporting this model and left its customers to deal with the problems themselves. This explains the fact that the company's representatives stopped in any way to react to customer reports about problems that have arisen, which are clearly of a technical nature on the part of the manufacturer. This is my last device from your company! I spent a lot of money on the purchase of your product, and you act so ugly with your customers, leaving them and do not even deign to reply to messages! Shame on the company!