The guy of the youtube channel Retro Game Corps reviewed UM690 with Batocera and gave me this answer about our issue.
My question: I am struggling to make Batocera run on USB. Have you changed some Bios setting?
Answer: Hi, I didn’t alter the BIOS at all, but I am running the latest beta/development version of Batocera which works well with some recent Beelink and MinisForum PCs. So if you have access to a different PC I would start up your Batocera USB drive with that PC, update to the development channel in the update settings, then try it in the UM690.