Did you mount the partition to /mnt/sysimage before attempting to chroot it? You can use the ‘mount’ command to see what’s mounted where.

I found this to be more or less impossible on my AM4 platform. The AMD RAID kernel module didn’t work under any distro. Fire up an Ubuntu live environment and see if you can detect and read the contents of your Windows environment. That should give you a good sense for what is possible. Otherwise I recommend installing to a separate NVME as I have.