@Sunshine 

Hi,

the router I bought (TL-MR6400EU V4) has a very low wifi and cable connection (about 1.7Mbps while with a phone router is up to 70Mbps) and sometimes keeps disconnecting.

I tried to set up and I've checked the firmware but nothing works.

Model number: TL-MR6400 v4 00000002

Firmware version: 1.16.0 0.9.1 v0001.0 Build 191223 Rel.66638n

Country Version: EU

I've tried creating the network profile manually or update the ISP profile but nothing changes, still poor and unstable connection. 

The band info is: 8

please, consider I'm working from home, remotely and far away from where I bought this device. It's disappointing that I've spent 70 euros for something of such a poor quality. 

@ashakantasharma the frequent 4G disconnect issues I reported two weeks ago still persist. It appears TP-Link customer/tech support haven't been around for a while. Under these conditions, I'll have to advice you to purchase a device from a different manufacturer (not a different TP-Link model). It appears these issues have riddled a number of TP-Link modem routers aside the MR6400.

Honestly, if these are hardware issues that can't be remedied with a firmware upgrade, or if TP-Link isn't willing or able to commit programmer resources to remedying this issue with a timely firmware upgrade, it would be in order to recall the MR-series as unfit for the purpose they are marketed for, and provide either refunds or replacement devices from a working router series.

@redovidiu thank you for confirming the my suspicion/observation on idle internet leading to disconnects!

"...an online radio station runs all day in the background and there is no disconnection from the network. When there is no more random network traffic, the router starts to disconnect."

I can confirm from my end that e.g. running a low-speed BitTorrent stream on the background effectively prevents these disconnects. I also wrote a simple keep-alive script that generates network I/O traffic at 30 second intervals, however that didn't cut it. It seems that the traffic frequency has to be near-constant to prevent disconnects. This is not a fix though! Unnecessary WiFi/internet traffic eats my laptop's battery, and as such this isn't even good for a temporary measure, except for critical no-die-net situations.

I doubt that the disconnects are ISP-triggered, given that our phones experience no such issues with the same provider. But even if it were: It should be easy enough to create a routine for the router that generates the necessary frequency of minimum bandwidth traffic to keep the connection alive even when no users are accessing the internet. Or, at the very least, the router should be able to immediately start a link recovery routine, rather than just doze off until poked enough!

With the background information provided here, this issue should be easy enough for TP-Link tech support to replicate and remedy. If not, please by all means let us know what further information you need to get this sorted.

P.S. System log in Debug mode just shows the same old, per my earlier post. However, there's been a new development. In that sometimes syslog logs absolutely nothing on what's going on with 4G. I've just had two disconnects, confirmed after logging into the router, with manual reconnect, however the syslog only shows DHCPD entries, even after attempts to refresh. I hope this isn't a sign of things to come, I'd really not care to buy a new router mere months after getting MR6400!

@MarkusAO 

As I mentioned in my posts above, the router is used at a location in the country where I have access to ONLY ONE CELL OF THE MOBILE OPERATOR. A few minutes after any traffic stops, the router goes into "hibernation", without recovering on its own. I brought it from there to the city where I live to take it for "repairs" to the store where I bought it. I put it into operation before taking it and ... surprise. For almost 48 hours it did not disconnect even once. I logged in with two phones and a laptop without the slightest traffic and it didn't crash. I disconnected with all the devices (zero traffic!) and at the first connection after 30-40 minutes it woke up instantly! The only difference is that there are about 3-4 cells of the mobile operator here. Can someone who wrote in this topic confirm if in the area where he uses the router there is only one cell of the GSM operator?

Can anyone suggest an idea how to write a subroutine in the router for a permanent ping in google to keep the router "awake"?
I'm trying this because I don't think I can prove to the service people that the router disconnects where I need it .... my location in the country ...

@Sunshine 

Hallo, I have the same problem, many disconnections every 5 minutes. Please send me the beta firmware. Mr6400 EU v.4

@redovidiu  "As I mentioned in my posts above, the router is used at a location in the country where I have access to ONLY ONE CELL OF THE MOBILE OPERATOR. ... Can someone who wrote in this topic confirm if in the area where he uses the router there is only one cell of the GSM operator?"

While I'm not exactly at the epicenter of all signals, we do have a couple of providers with towers in my neck of the woods. I understand my operator only has one tower nearby, the rest are a bit out there (when the nearest tower goes dark, signal drops dramatically). Current signal strength at RSRP: -95dBm, RSRQ: -10dB, SNR: 10.4dB. Which seems above average for me, most of the day it's more crowded and closer to/above the -100dBm mark.

I took the router down the road the other day (needed a very quiet space for work), where the signal is much stronger. Still disconnected a couple of times before constant traffic (Zoom) kicked in. I've got a good little UPS here, guess we should go camping with Mr. 6.4K to troubleshoot and try internet at random places?

On an update. It's taking more clicking-around than it did in the past to get the disconnected router back on the internet. Used to be able to resove it in a couple of clicks to stimulate it back into action. Now it's often taking a dozen tries, a logout/in, flip 4G/3G/4G, Data on/off, and occasionally reboot. To a point where it's an irritating interruption.

• @ TP-LINK TECHS/MGMT :: SERIOUSLY. YOU NEED TO WEIGH IN HERE. SAY SOMETHING. We're getting to a point where I'm gearing up to hang the router from a treetop, instagram the sight with this story, and toss it all over the cyberland. For laughs yes, and as a matter of public service advisory re: TP-Link products. I hope there's a solution or at least a substantial update/advisory forthcoming soon.

@Kevin_Z 

Hello, I am having the same problem. Please help me my device is  MR6400 V4.

@Kevin_Z 

there is some bug in the product, when I connect to the internet using 4g network, several times during the day the device automatically disconnects from the internet and starts again when I restart the product. Also, it stops the connection from the internet if no device is connected to the router.

The firmware in the router is the latest version: 1.10.0 0.9.1 v0001.0 Build 190521 Rel.38696n

And Hardware version of the device is: TL-MR6400 v4 00000002

Kindly take this matter into account. And help as soon as possible. PLEASE......