.\ffmpeg.exe -i .\kayoko.mp4 -ss 00:00:00 -to 00:02:20 -c:v libx264 -crf 18 -preset slow -c:a aac -b:a 192k output.mp4
forum #438402

@GabrielWB
Why would you transcode it? Isn't your goal here only to trim?

hdk5 said in comment #2598098:

@GabrielWB
Why would you transcode it? Isn't your goal here only to trim?

@hdk5
It absolutely was. The reason being that I'm just so used to using -ss for time related edits, but using that in combination with -c copy results in a corrupted file with mangled keyframes. So I just blamed the video file and went for the transcode with the same settings.

I see that you and WRS have already stepped in and replaced it with a properly trimmed version using -to, which is what I should have used in the first place.
Thank you both for stepping in. A learning moment for me.