@icedquinn
It could have been interlaced broadcast recording or an older DVD. Those are VFR at times (mix of progressive and interlaced content). The "fix" is to either play them back on proper deinterlacing supporting player or deinterlacing them with ffmpeg. Deinterlacing with 2x framerate (bobbing etc) results in a bigger file, but obviously smoother motion.

Was deinterlacing what chatgpt recommended? Or did it tell you to drop frames or something?
@jamie