You're most welcome, Anthony 
By the way: I've just tested the playback of a Commercial DVD movie that I own in an old "HP Pavilion dv6" laptop computer that still has a DVD drive, and that is running the recently released Ubuntu MATE 23.04 (Lunar Lobster). When I inserted the DVD disk in the drive, I got a dialog box prompting me to open it in Celluloid, but when I accepted that, I got the same error that you got:
Error
Playback was terminated abnormally. Reason: no audio or video data played.
OK
I got that solved by:
1 - Installing the "ubuntu-restricted-extras" package (maybe not necessary?): sudo apt install ubuntu-restricted-extras
2 - Running sudo apt install libdvd-pkg
3 - Running sudo dpkg-reconfigure libdvd-pkg
4 - Reboot.
After I have done that, the DVD movie started playing correctly in "Celluloid".
I suggest that you read the related following article, if you haven't already: "How to Play DVD in Ubuntu 22.04, 20.04 and 18.04" - https://itsfoss.com/play-dvd-ubuntu-1310/.
By the way: you wrote that you "had no problems playing DVD's on Focal [ Fossa (20.04) ]" but I found that you had posted a similar topic back in July 2022, when you were running Ubuntu MATE 20.04 (Focal Fossa). In that topic, you were helped by @Drc (Brian) although you haven't replied back in that topic. Do you remember if you tried @Drc's suggestions back then and if they worked for you? Link to that topic: