Wikipedia has more details about Babylon 5's transfer issues. They shot the show on Super 35mm film so they would have a widescreen source, which they telecined down to 4:3 for broadcasting. But when the show was remastered for widescreen in the 2000s, the production company did not return to the original widescreen film. They converted a 4:3 PAL copy to NTSC and then upscaled that to widescreen!

https://en.wikipedia.org/wiki/Babylon_5#Mastering_problems