I have the same problem although on a VR600 model. My devices connected to the 5ghz band suddenly drops and cannot reconnect until I reboot the router. I can see the 5ghz network, but nothing connets. A reboot fixes it, but it's not a solution... I tried changing the wifi channels, turn wireless off and on again and played with all the settings, but with no luck. TP-Link should look into this and fix it! I'm pretty sure it's just a quick fix for a  softwere glitch...

There is no error message and all devices fail to reconnect. They start connecting, than just stop without any message. They all connect to the 2.4ghz with no problems. I tried to change the channel width, I changed to different channels, firmware is the latest up to date one. I tried to play with all the settings, nothing worked but a reboot. Once the router booted up all the devices connected to the 5ghz band immediately and they are still connected in the last 2 days. I'm just wondering when they will be dropped again... The last time it was about 3-3.5 days till they got dropped off and couldn't reconnect... 

Thank you Kevin for your reply! Yes it does support auto reboot, however I got this modem to replace my BT (not so-)Smarthub and maintain a stable connection without any reboot. The smarthub rebooted every 14 days and it drove me crazy... Sometimes it was 14 days exactly, sometimes 14 days and 1 hour etc... Even if the internet was in use. The vr600 seems rock solid and stable to maintain the connection without any reboot, but the random 5ghz band drop is a huge let down for me. Do you have any idea why this could happen? Browsing different forums I can see it's a known issue and many of the devices, used and new ones are effected. I have the EU v2 version and the last firmware for it was released in 2017. Is there any possibility something new will come out for it? The AU version has just got a firmware update this August.

@matekaneve 

im having the same issue with my unit. 
iphone wont connect saying incorrect password. No device will connect.  
even setting the auto reboot it won't always work. 
why haven't tp link fixed this. 
 

I use an Archer AX6000 

same problem with an archer 400 , 5g is dropping frequently 

@jay1234 Same issue with me and it only appeared a few days ago!! before that everything was perfect

jay1234 wrote

Hi I’ve just got this router I upgraded the firmware to the latest version, first problem is the bedtime mode on parental controls doesn’t always work. And the past 2 days when I wake up in the morning the 5ghz doesn’t work and I have to reboot the router to fix this.