Comment # 7 on bug 1202438 from Hansi Meir

So sorry, I made a mistake on last try, there was an USB stick I forgot to
remove . So hd1 was not the same as before ...

I did it once again without USB stick (and disabled TPM) and then the old 
error: ../../grub-core/kern/mm.c:372:out of memory
occured again. 

Sorry for that ... facepalm ....

Then I tried a few files from NVMe2. 
One from my /home on gpt3, a jpg with 2,6 MB size in the download path, grub
found it.

Then I tried the other iso files in gpt5/boot/iso, grub only found one of it.
It was SuperGrub2.iso and this file has only 15.6 MB size. All the other files
are much bigger from round abound 700 MB up to 1.1 GB (the rescuzilla.iso).

I tried also another small file in gpt5/boot/iso/ventoy-1.0.79/README and grub
found it.

May be file size makes the out of memory error?