Thanks, Moro. I already have the latest libgstreamer stuff.
I speculate it is just an example of developers not caring about old technologies. Who burns CD's anymore? It seems to have started with the advent of systemd. I have several laptops. Sometimes the problem does not occur, but I never remember which laptop and I think it is inconsistent anyway. Oh, well, not a big deal. Thought someone might know a light-weight substitute for xfburn, which has served me well for years. Brasero is quite heavy, and does not always work either, if I recall correctly.