@Kathy_Z 

I have the same issue. It is my first purchase of TP-Link, I just bought this wifi dongle yesterday to solve an issue with my internal wifi chip.

It is not possible to have these issue for a recent product, and for so long. When a fix will be available ? According to your answer, I will decide to buy another brand.

Thanks

@SrLan 

For all who would have the same issue, please refer to the following suggestions:

1. update the driver to be the following one: https://static.tp-link.com/2019/201911/20191128/Archer T3U_beta_U2_U3_5G unstable issue_1030.22.0202.2018.zip
2. (If the above driver did not work, please also try this one: https://static.tp-link.com/2020/202006/20200601/00015960-RTLWlanU_WindowsDriver_1030.38.0712019_Drv_3.00.0032.L.zip)
3. set up the static IP address on the computer or reserve a specific IP address on the router for this computer;

If the above suggestions did not help, please send an email to support@tp-link.com： subject# Forum 187862 Archer T3U drops 5 GHz connection after Windows 10 1909 Update,  with the following answers and our senior engineers would help you run further test:

1. How long have you had the device and when did the issue start?
2. Did it work fine before the windows update to 1909?
3. Except for the 5ghz, is the 2.4gz working flawlessly?
4. When the 5Ghz connection lost, is there any error message such as the default gateway is not available?
5. What is the system info and driver info on the computer, such as https://www.tp-link.com/support/faq/2722/?

Thank you very much for your cooperation and support.

@SrLan 

On the contrary, Asus is a scam.They sell the AC53 with AC1200 specs, but the device is USB 2.0, so anything more than 480 Mbps is physically impossible.

I have exactly the same issue on Windows 10 Pro x64 Update 2004. I followed all the hints posted here. Nothing works for me.

Send an email to the support with answers for questions posted by @Kathy_Z . I will let you know when I get any useful answer.

@BabyRain 

Good day.

Thank you very much for your time and patience.

Sorry for the delay.

Did you want to install the official driver or the beta driver posted on previous thread?

Have you tried to install the driver in the safe mode and turn off the firewall to have a look:

https://www.tp-link.com/support/faq/791/

and there is an instruction about how to update the driver manually:

https://www.tp-link.com/support/faq/920/

Thank you very much.

@BabyRain hello my friend.

TP Link d'ont care. Buy a asus or D Link dongle, like I did, and be happy.

Confirming the same issue here :( 
Slow wifi speed now and dropping connection every 5 mins or even more often. Tried provided drivers, disabling firewall  - nothing helps, just annoying :(