I'm having the same issue with 16. During boot from media, I get the following error.
'Failed to open \EFI\BOOT? - Invalid Parameter'
'Failed to load image \EFI\BOOT? - Invalid Parameter'
'Start_image() returned Invalid Parameter'
I tried re-downloading the image the next day. Also tried creating the flash media using Belena, Rufus and Universal USB boot creator.
I have a Dell optiplex 7070 with 36 gig Ram and Intel HD graphic. I have had several different Ubuntu based distros on this computer in the past, including 21.04.