I have installed Windows Ubuntu 11, from https://www.wubuntu.org/The problem is the grub is not detecting my hard drive and it started where I installed the latest drivers for Ubuntu using the code ubuntu-drivers install.I think the grub was updated to latest version.
So, I have tried setting GRUB_DISABLE_OS_PROBER=true or false, which did not work. Afterwards, all I see is GRUB_DISABLE_OS_PROBER, and my mnt folder is empty too.