Can't run memtest?

Hello, I have a Librem 15 v4, PureBoot-beta-13, linux 4.19.0-9-amd64.

I can’t seem to find a way to run memtest even though it’s in the default boot menu for the system. The best error info I’ve gotten so far when I try to boot it from the boot menu:

Loading the new kernel:
kexec -l /boot/memtest86+.bin --append="intel_iommu=on "
Cannot determine the file type of /boot/memtest86+.bin
Failed to load the new kernel
Failed to boot w/ options: Memory test (memtest86+)|elf|kernel /memtest86+.bin

Sorry if there may be some small errors in that text, as I had to take a video of it and transcribe it to be able to get enough of it down.

I’d also appreciate if anyone confirms they CAN run memtest with a system like this