I just noticed the issue again. So I closed the video, renamed the old celluloid config to ~/.config/celluloid.old and played the video again -- the issue was gone. Out of curiosity, I deleted the new ~/.config/celluloid file and tried the old ~/.config/celluloid file -- the issue was still gone. This is utterly bizarre! 😕

Yes I do agree. I do not see how a new config file can fix an old one.

I tried a new config file to rule out if the issue was with the old config file. It seemed to be. Then after trying the old config file again, the issue is still gone - so the issue is likely not with the config files. It's a real puzzler.