Linux Installation notes for Kernel 4.4.x to 5.x (Advanced Linux Technician required)
Internal photos on the FCC report shows what appears to be a RTL8811CU chip used during the radiation testing, this also is the chip that is used in the final production so we know that this is the chip used. The Linux driver for this device as provided by UGREEN seems have difficulties. The driver states that it is for the RTL8821CU chip which is ok as there seems to be some similarity, but there are issues with it.
What is needed is the driver that is located here at github https://github.com/brektrou/rtl8821CU
From a technical standpoint we can't supply a compiled driver because it needs to be compiled to your computers CPU architecture. If you can't access github the driver is below. Also the compile instructions are below.
Realtek RTL8821CU USB Wi-Fi adapter driver for Linux
File: rtl8821CU_rtl8731AU_v5.8.1.5.zip
7f0445ccdc5e7c55baaa2a66b698fa2172d01fa4245e0519fde3943ee33cc018
Realtek RTL8811CU/RTL8821CU USB Wi-Fi adapter driver for Linux
File: rtl8821CU-master.zip
4e605fa9bd053044bec0efcdd295ccf403632ce58948ac6f29b08552b09995f5
Realtek RTL8811CU/RTL8821CU Compile Instructions
File: realtek-rtl8811cu_rtl8821cu-usb-wi-fi-adapter-driver-for-linux.pdf
26a19c0228f1aaffa0c13aed4f9ef01edea09a63b02eadaed31854fad9e55f06
