@CHUHY 

Hi, kindly check this article for more details to confirm if the QoS settings on the AX3200 is configured incorrectly, you can try to disable it if necessary:
https://www.tp-link.com/support/faq/3069/

Just to confirm, what kind of wireless devices you are testing the 5G connection with the AX3200, can we have the brand and model of it? If it is a computer, we would like to know the model of it, please ensure it is running with the latest driver, thanks.

You can also check and modify the 5G wireless settings on the AX3200, you can check that by installing an app like Wi-Fi Analyzer on your phone or laptop and test, then set a channel with less congestion according to the test results on the AX3200.

Additionally, please check this troubleshooting article for more suggestions:
https://www.tp-link.com/support/faq/2170/

@CHUHY 

My wireless device that I use to test is iphone 12 Pro Max. The app that I use to test on the phone is Speedtest app and on my wired desktop is via the same Speedtest.net site.

Phone is right next to the wireless router. (1 feet or less)

Wired no problem. Its the wireless upload speed which is 1/2 of what I should be getting.

I have already reviewed the two articles that you have provided, and have tested the following:

Disable QOS (unchecked the QOS box).

Smart Connect enabled or

Smart Connect disbled with the following settings.

set the 2.4 GHz to 20 Mhz, 5 GHz band 1 to 40 Mhz, 5 GHz band 2 to 80 Mhz and

set the 2.4 GHz to 20 Mhz, 5 GHz band 1 to 80 Mhz, 5 GHz band 2 to 80 Mhz.

set the 2.4 GHz to 20 Mhz, 5 GHz band 1 to 80 Mhz, 5 GHz band 2 to 40 Mhz.

tried the iphone device on either 5 GHz band 1 or band 2.

All of the above still produce the same result using wireless device for speed test. 

That is download 400 + Mbps (no problem) but upload only seeing 1/2 of the promised speed (200 + Mbps). At best I see only 270 Mbps upload. 

Again, I do not see this issue using my 5 year old Verizon FIOS G1100 router (dual band), which shows 400/400 wired and wireless speed test.

Please advice.

@CHUHY 

Thanks for the details. If that is the case, we would like to investigate the issue further by following it up via email, please check your email box and respond.