Welcome to the forum
I think that the cause is the RW disc. Different drives have different reading capabilities, and apparently your old Liteon was a better reader than the current LG.
Try to read the discs with a different drive. You can as a friend to do a little test, just to see if the disc is readable or not.
Try also to use a brand new disc on the camcorder and see if the LG is able to read that disc. Rewritable media can become unreadable very quickly