Looking at the code in grub-core/osdep/linux/ofpath.c, the issue is most likely that the buffer that of_path is pointing to of_path_of_nvme() is not large enough to hold both the contents of *of_path and disk[MAX_DISK_CAT].
Let me test a patch. Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaub...@debian.org `. `' Freie Universitaet Berlin - glaub...@physik.fu-berlin.de `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913