@PETzz @MWarren90

The QoS and device priority is what trigger the 250-300Mbps issue, disable all (QoS on Standard) and with no device with prioritization. 
I have a 1Gbps with my ISP and I can replicate the issue always, any of those parameter active and the THP goes down to 250-300Mbps. 
 

@CristMog I know, but people keep saying again and again that it's the app.

It is NOT the app. It is the QoS & Device Priority.

@PETzz I've literally never touched the QoS or device priority aside from looking at the tab and moving on. I've never changed those setting away from the default which appears to be "Standard" and no devices selected. How would QoS or device priority be the issues if they were never utilized from the factory default? 

I can confirm it is QOS and not the Tether app itself. I turned off device priority and did a reboot and I'm getting double the wifi speeds I have been struggling with. for months. QOS literally breaks wifi, so irritating.

I'm having this problem with my ax50, 50% of my isp is all I can get. I've looked for how to turn the QoS off but I can't for the life of me find anywhere to turn it off.

I've been talking back and forth with tplink support trying to do different troubleshooting steps but no real luck. This is after I've already tried to do the tether app stuff and take it off all together. You can't really turn off QOS but i never messed with it to begin with after factory restores. Turning it on definitely does kill speeds. turning it back off just keeps me about half and lower of the speeds i should be getting.

Changing the "Internet Port Negotiation Speed Setting" from "Auto Negotiation" to "1000Mbps Full Duplex" did the trick for me, now I get the >700Mbps from previous 100-250Mbps dl speed. It looks like the modem is slowing down the router with lower WAN speeds if it is set to auto negotiation for some reason.

For my Archer AX50 v1.0 Firmware 1.0.9, the setting can be found in System Tools -> System Parameters -> scroll to the very bottom to "Internet Port Negotiation Speed Setting". And you need to switch to the Advanced tab of course.

Cheers,

Pascal

@David_vt deleted the app off my phone, reset the router......BAM! Finally getting the internet speed I'm paying for!! After months of frustration, thank you!!

@Carl did you not read the thread?  It's about the fricking app that kills your router?

My last experiment with tp link. I guess you guys get paid even if the router goes in the dumpster.