This is what your /boot/grub/grub.cfg or /etc/grub.d/40_custom should look like as regards RLRH. (An example of course).

menuentry 'RLRH EXTON - Rocky 230922 (sda7-Samsung_T5)' --class rocky --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-4525f0ad-5dc4-481b-bde0-c67f7f7fc697' {
        load_video
        set gfxpayload=keep
        insmod gzio
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt7'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt7 --hint-efi=hd0,gpt7 --hint-baremetal=ahci0,gpt7 4525f0ad-5dc4-481b-bde0-c67f7f7fc697
        else
          search --no-floppy --fs-uuid --set=root 4525f0ad-5dc4-481b-bde0-c67f7f7fc697
        fi
        echo    'Loading Linux 6.5.3-amd64-exton ...'
        linux    /boot/vmlinuz-6.5.3-amd64-exton root=/dev/sda7 rw acpi_backlight=vendor acpi_rev_override=1 
        echo    'Loading initial ramdisk ...'
        initrd    /boot/initrd.img-6.5.3-amd64-exton
}


If you want to use Rocky's kernel you shall replace vmlinuz-6.5.3-amd64-exton and initrd.img-6.5.3-amd64-exton with 
vmlinuz-6.5.3-1.el9.elrepo.x86_64 and initramfs-6.5.3-1.el9.elrepo.x86_64.img

When installing RLRH in VirtualBox or VMware you can switch between the installed kernels by running the commands below and reboot.

$ sudo dracut --kver 6.5.3-1.el9.elrepo.x86_64
$ sudo dracut --kver 6.5.3-amd64-exton

NOTE 1: You can only use Refractasnapshot when you have booted RLRH with "my" kernel vmlinuz-6.5.3-amd64-exton.

NOTE 2: You could possibly benefit from reading my INSTRUCTION "How-to dual-boot, triple-boot or multi-boot Linux with Windows in a simple way and be happy" - https://www.exton.se/how-to-multi-boot-linux/