@princery Hello, 

As this adapter used to be working it is recommended to fix router's wifi channel on 5Ghz and lower 5Ghz channel width to 40Mhz, you could scan for 5Ghz wifi using APP like WiFi analyzer and select a good channel for router. 

May I know the model of router and did you recently change router Wi-Fi settings or upgrade Windows version? 

@princery  Hello, 

Thank you for your reply, you could try 5Ghz channel 36/40/44/48, not on DFS channel or it could be unstable

Turn off Band steering/ Whole Home WiFi/ Channel or WiFi optimzing on the main router if there is any. 

DFS channel introduction : https://www.tp-link.com/en/support/faq/763/

Please try this latest chipset driver for  and see if help with the issue:
https://static.tp-link.com/beta/2021/202101/20210108/RTLWlanU_WindowsDriver_1030.41.0514.2020_Drv_3.00.0036(26078).zip

Below is the instruction to manually install driver:  https://www.tp-link.com/support/faq/920/

If problem still exist,  help us check the  computer motherboard info and send us the photos, thank you!  https://www.tp-link.com/support/faq/2722/