@myne I think your problem is to be trying to boot via UEFI (I understand that you can not change this, but it seems that's the problem). You should try to boot via USB, this would be a test: if that is the problem, it will not boot from USB. If you can boot from USB, you will know that the problem is not UEFI.
I do not know how to help you, but, I know there is a tutorial here in the forum (in French), which teaches you to do dual boot, even by UEFI, it might be useful for you to read:
https://forum.recalbox.com/topic/15678/dualboot-recalbox-windows-sur-pcs-laptops-avec-bios-ou-uefi
As I do not know this "Compute stick blkstk1a32sc", it might be a driver incompatibility, and you will not be able to boot in any way, but just testing the other possibilities to make sure that's it. To avoid incompatibility issues, use the latest official version:
https://archive.recalbox.com/