Ventoy wimboot get "out of memory"

[msauv]

I have 2 computer, one with 2G and one with 50G RAM
My Ventoy USB works properly on the one with the less memory.
With the same USB stick, on the one with 50G at least one wimboot fails. With an "out of memory" when asking for 9M.
Has somebody seen this before?
So it seems that the memory available to grub is limited and depend on the computer.
I did not found a related grub parameter or BIOS option. (The mem parameter is for the chosen kernel later)

Here are more details if it helps:
I generated Ventoy to debug with additional debug traces. (Because Ventoy grub console does not display the out of memory)
Both use the same code in the generated grubx64_real.efi

The problem is in ventoy_read_resource (called by ventoy_cmd_locate_wim_patch, ventoy_wimdows_locate_wim, search_replace_wim_dirent, parse_registry_setup_cmdline)
on the line: buffer_decompress = (grub_uint8_t *)grub_malloc(head->raw_size + head->size_in_wim);
grub_malloc return null. SO not enough memory.
At this point one the not working computer cannot allocate the required 10M the other still have 500M available.