@Tom-Elliott Hello again,
First of all, thank you for the suggestion. After the boot process starts, it attempts to PXE boot. Then, for a fraction of a second, the following message appears before it returns to the BIOS. I think the issue might be, as you described, related to trying a different type of PXE boot.
https://ibb.co/SJbg4LR Order of Boot
https://ibb.co/DgpS4Ht error