According to the screenshot, the reason of dropping to initramfs is that root partition was not found. There could be two reasons for that:
- UUID is not correct in GRUB's kernel menu for root parameter
- LVM has not been loaded by initrd and since your root partition is on an LVM volume it was not able to find it
To verify if it's #1 or #2, run the following commands in initramfs console:
blkid | grep <uuid that you see on screen>
If the UUID is found then it's #2 (LVM was not loaded by initrd), and you should follow this link: Can't find LVM root dropped back to initramfs
If UUID was not found, you will simply need to provide the correct UUID in root parameters of your GRUB menu.
To figure out what the right UUID is run blkid to see what is assigned to the root partition. There is usually a 'root' word in the partition mount point, e.g. on my machine blkid would show something like this:
/dev/mapper/ubuntu--server-root: UUID="9daacbc2-160c-..." TYPE="ext4"