Can't change Titles on subsequent chapters

I have a DMR-ES20. I have successfully edited chapters in the past before finalizing. Now after I changed the title on 1 chapter thru the Sub Menu, I can’t get the Sub Menu to come up to change titles on any other chapters. I was able to do the disc title.

You can name titles but not chapters

I mis-stated the problem, it is not chapters, it is titles. I can’t change titles on more than 1 of the recordings on the same disc. After I changed the title on 1 recording thru the Sub Menu, I can’t get the Sub Menu to come up to change titles on any other recordings. I was able to do the disc title.