Well the media info you posted shows the original file is not a matroska .mkv but TS ( transport stream) If you made the samples using mkvtoolnix or makemkv and they play smoothly that would explain why.
Just remux the original file in full not just clips of it.
I downloaded the clip and looked at media info and it says
Format : Matroska while the media info of the original says Format : MPEG-TS
@k2u3 - so just remux the whole file using mkvtoolnix and see what happens? I split the TS using mkvtoolnix with default settings. Should I change something in the setting?
Not really. You’d have to ask @grahamh or @sam_nazarko or someone else that understands how kodi works. I was told that matroska provides some meta data to the player upfront that probably helps but I’m just guessing