@DanHarvey for comparison, this is network performance using laptop wifi adapter, during a video call (hence the higher throughput). Same location, same wifi etc.

  @Solla-topee I really struggled to work out how to force windows to use the TP-link driver, it just told me that the driver it was already using was the right one. In the end by pressing "update driver" and then "browse manually" and then "let me pick from a list of available drivers" I happened to choose one that was there that worked. It is a windows driver I think, 1030.38.712.2019

  @Solla-topee the issue has now resurfaced with the same driver installed. Not really sure where to go now!

  @Solla-topee thank you, it looks like that latest driver has done the trick. I'll be in touch if it starts dropping out again!

Solla-topee wrote

Hello  @DanHarvey 

Here is a chipset driver for Archer T9UH, you could give it a try and see if it helps improve the performance. 

Realtek Chipset Driver for T9UH (Win7/Win10)

 

If still the same, can you help confirm  some information here for us to investigate further

1. When the connection lost, was the Wi-Fi still connected but no internet or speed drops to 0? 

2. How can you recover the connection,for example manually reconnect Wifi or it will recover itself.

3. Does this only happen when you use video call, what software do you use when the issue occurs. How often does that happen 
 Please send us a photo of  the driver version and computer system information by referring to this FAQ :           https://www.tp-link.com/support/faq/2722/

  @Solla-topee 

Hello!

I bought the T9UH yesterday and had been having the issue whereby the connection would randomly drop out when connected to 5G. It's like the driver goes off searching for 4G even though you've told it not to and it gives up when it can't find it. After trying numerous posted solutions, installing the above driver does seem to have worked. At least it hasn't dropped out yet. This issue has been going on since the T4UH and I'm really surprised that it still persists to this day.

From what I can tell, the one common denominator in all this seems to be Realtek, great at hardware maybe, rubbish at compiling drivers. I swear I had an old Asus years ago where drivers were causing the same type of issue. If you are developing the T9UH V3 or even a T10UH, either don't use a Realtek chipset or at least compile drivers that work straight out of the box.

Anyway

Many thanks for posting your driver, fingers crossed it keeps working!

CHEERS!