I have the same issue on Cinnamon, send me back to Grub menu. Installation went fast with no errors, almost too fast. I did reboot it left to count down, managed to take a photo of this error:
error: start_image() returned 0x8000000000000001.
Failed to boot both default and fallback entries.
Idk what it error means or what else I can do, only got access to Grub command line. I’m not sure if my ISO got corrupted during download in waterfox, it failed so I just continued until it completed. Re-downloading now.