It's very weird, in the grub shell, it does show that there is no files in the Ventoy exfat partition.
When you reboot to your linux system, did you see that the ISO files still there?
Please give your shell command result. For example, you can run the following commands in your linux shell (assume that the Ventoy USB stick is /dev/sdb).
mkdir abc
mount /dev/sdb1 abc
ls -l abc/
When you reboot to your linux system, did you see that the ISO files still there?
Please give your shell command result. For example, you can run the following commands in your linux shell (assume that the Ventoy USB stick is /dev/sdb).
mkdir abc
mount /dev/sdb1 abc
ls -l abc/