Since nobody here yet has cared or knows to answer I did some research on the problem, since I've never encountered it myself.
Syslinux the way it is setup in the live image is meant to be a 32bit subsystem and those files are its own internal files it can not load. I assumed for being able to find the syslinux directory the image is correct, but is it?
How do you flash the image into the disk? Do you use windows or some program in linux to copy the image into the flash drive? Rufus maybe? Get the sums file for the base or jwm image you are using
https://repo.obarun.org/iso/2021.09.01/md5sums.txt as root:
# cat md5sums.txt
# md5sum obarun-JWM-2021.09.01-x86_64.iso
# make sure the number is the same as int the md5sums.txt for the image
# dd bs=4M if=obarun-JWM-2021.09.01-x86_64.iso of=/dev/sdx status=progress oflag=sync
where sdx should be replaced by your flash drive designation, /dev/sdb /dev/sdc etc.
it takes a few minutes
If you are in fact using some software gui to do this it may be transfering the antiX image correctly but failing for the obarun image.
The obarun image senses whether it is bios or efi booting and works accordingly, and this functionality seems broken on your image.