I would like to take up the topic again. 
This rtl8812bu USB Adapter wont work (lsusb output):
Bus 001 Device 002: ID 0bda:b812 Realtek Semiconductor Corp.
I am using the actual snapshot (ATH79) for my GL.iNet GL-AR300M-Lite.
OpenWrt SNAPSHOT r12576-f2d976f06e / LuCI Master git-20.074.84698-03af89a
I have already installed:
kmod-rtw88 4.19.108+5.4-rc8-1-1
I only see this message:
[ 563.105752] usb 1-1: USB disconnect, device number 2
[ 566.248085] usb 1-1: new high-speed USB device number 3 using ehci-platform
Any hints for me ?
regards