I’m not familiar with the brand, but general ideas that come to mind to troubleshoot are:

• Disable secureboot if enabled. Understanding you’ll lose that security feature of course.
• See if there’s an option to mark your storage as removable in the installer (–removable flag in grub iirc). My (pretty old) motherboard does not seem to respect attempts to add uefi entities but it happily boots off a “removable” uefi install.

Quick q: do you use all the space available or partition your disk?