xinput listis there USB KEYBOARD ?
sample USB KEYBOARD id=15 [slave keyboard (3)]
and so write
xinput set-prop 15 "Device Enabled" 0 xinput set-prop 15 "Device Enabled" 1
That works! https://askubuntu.com/questions/819148/lock-builtin-laptop-keyboard-but-keep-an-external-usb-keyboard-functioning 
sudo apt-get install efibootmgr sudo modprobe efivars Then run sudo efibootmgr to check your boot entries ex) BootCurrent: 0004
Timeout: 2 seconds
BootOrder: 2001,0003,0005,0006,0000
Boot0000* Lenovo Recovery System
Boot0001* EFI Network 0 for IPv6 (B8-88-E3-84-F3-EF)
Boot0002* EFI Network 0 for IPv4 (B8-88-E3-84-F3-EF)
Boot0003* Windows Boot Manager
Boot0004* EFI USB Device (SanDisk)
Boot0005* ubuntu
Boot2001* EFI USB Device sudo efibootmgr -b 5 -B https://askubuntu.com/questions/63610/how-do-i-remove-ubuntu-in-the-bios-boot-menu-uefi $ sudo dpkg -i package_with_unsatisfied_dependencies.deb
dpkg: dependency problems prevent ...
[additional messages]
$ sudo apt-get -f install
[apt messages]
Setting up [dependency]...
Setting up package_with_unsatisfied_dependencies... https://askubuntu.com/questions/40011/how-to-let-dpkg-i-install-dependencies-for-me sudo rm /var/lib/apt/lists/* -vf sudo apt-get clean
sudo apt-get autoclean
sudo apt-get update
sudo apt-get upgrade source: https://forums.linuxmint.com/viewtopic.php?t=193973 sudo apt update
sudo apt install git
git clone https://github.com/gnab/rtl8812au.git
sudo cp -r rtl8812au /usr/src/rtl8812au-4.2.2
sudo dkms add -m rtl8812au -v 4.2.2
sudo dkms build -m rtl8812au -v 4.2.2
sudo dkms install -m rtl8812au -v 4.2.2 and reboot is it working? https://askubuntu.com/questions/991643/rtl8812au-usb-adapter-driver-issues