@Sevi 

Some older non-AX devices have had issues when AX is active on a specific band.  You can try disabling the AX on each band and try to test.  Also we did have a recent issue affecting the AX50/AX3000  https://community.tp-link.com/us/home/forum/topic/187502.  This is specific to a device but could be a factor as well.

@Carl I'm getting this is well.  Speeds directly from ISP are correct.  Speeds from the router are tragic.  Lan is performing worse then wifi.

@Mrxjesse 

Can you provide more details on the issues you are experiancing with the LAN?  For the Wifi please try to turn off the AX setting on each band and see if that fixes the issue.  If so let us know. 

@David_vt 

I did all this and can confirm this fixes slow download speeds.

I have telus gigabit internet. I was getting 250-300mbit max and fluctuate like crazy. I had the teether app installed. 

After uninstalling the app and reseting the router, i reran speed test and boom! 450mbit now from the wifi6.

Definately a bug here too. Hopefully tplink reads this and fixes it.

Shaun

@Carl Has TP-Link fixed this yet or can we not download or link the router to the TP-Link Tether app still?

@JoelS 

The issue with Legacy devices working with AX enable is not something we can fix.  That has to be fixed with firmware or software updates for those specific devices, as it is a device level issue.  

If you are referring to the issue with Samsung devices,  Yes that was fixed with a firmware update this is available now.

@Carl Multiple users said it was the Tether app causing their issues? Did this end up being false everyone?

@JoelS 

Hi Joel,  I haven't seen any reports of that.  The Tether app is no different than any management app.  You have local access on the same network of if your router is connected to a TP-Link ID you have cloud/remote access form outside your home network.  If you can point out any other threads or elsewhere where tether is being stated as a problem i'd be happy to look into it.