If QEMU displays OK then the problem must be with the physical PC, PC BIOS or USB drive.
So try different PCs,
try different USB drivea (different types and different sizes of USB drive)
try different filesystems for Partition 1 (exFAT, NTFS, FAT, etc.)
What PC are you using? What USB drive are you using?
So try different PCs,
try different USB drivea (different types and different sizes of USB drive)
try different filesystems for Partition 1 (exFAT, NTFS, FAT, etc.)
What PC are you using? What USB drive are you using?