Hey folks,
TL/DR: after a botched setup, my Mi Box S just boots straight into the Welcome / language selection initial configuration screen and stays there, and the remote is completely useless because it was previously paired but now it won't do anything.
Edit: Plugged in a USB mouse and/or keyboard to the USB port (both work!) to go through Setup. From there, I could delete the paired Remote & add it again.
Have you tried plugging in a usb keyboard / mouse to complete the setup and then tried to pair the remote?