Slow speed on Ubuntu, ZyXEL AC600 (NWD 6505)

AyPavlov

I use Ubuntu 20.04 LTS, Dual-Band Wireless AC 600 USB adapter (model name: NWD 6505), the router works at a frequency of 2.4 GHz. Under Windows, the download speed is about 20 Mbps, and under ubuntu, about 3 Mbps. Of course, on Windows I installed drivers from the official site. But I do not know  how to do this on ubuntu. 
Please help me, how can i improve the speed of connection?

Zyxel_Eric

Dear Sir,

Driver for NWD6505 only supports Mac and Windows system.
It didn't support Ubuntu.

Best Regards,
Eric