Now, after setting QoS to 1023999 kbps upload/download and to standard. Speeds are above 30mbps ONLY on wifi to wan and wifi to wifi. Any traffic passing through lan 1-4 is still capped.

@Locoxella 

Try swapping the Ethernet cable being used on the WAN port and LAN, also if you have Tether installed on your phone, remove it then do the speed test again.

Hi! 

I had the same problem, only after disabling QoS the situation went back to normal.  

@Tony I'm having a similar problem; I have gigabit internet & the AX50.  My Chromebook gets up to 630 Mbps directly plugged into my Arris S33 2.5 gigabit modem.  As soon as I connect my AX50 my Ethernet speed goes down to 200-250 Mbps.  Every wifi device in my house gets 130-170 Mbps (including my iPhone 12).  Are you saying the solution is to delete Tether off of my iPhone?  If I delete Tether & then reinstall it will it automatically detect my network name & passwords?

Thank you.

  @Locoxella 

I am surprised that tether application is causing this issue. I was getting speeds upto 60mbps when the tether app was installed :

1. Clear cache, clear data and uninstall Tether app. - [On my Android phone]
2. Updated my router (Archer AX3000 v1.0) to firmware 1.0.4 Build 20200426 rel.69563(5553) - check your hardware version before updating - there are 2 different HW, so potentially different firmwares. 
3. Ran the speed test - still 60-70 mbps
4. Reset my router and reconfigured (Keep the same configurations, so that all devices connect quickly).
5. After reconfiguring did a speed test and its 950 mbps now :)

so RESET is a must. 

Not that the tether app is a state of the art app or something. I can live without it. 

Thanks