closed captions not working after exporting as web type

Hi.

Wow, it's been a while since I last even thought about this!  To be honest, since then I haven't regarded the VTT route as being fully worth the effort - I just burn my subtitles directly into my videos nowadays, so that they're always there and visible.

To answer your question though, if memory serves me correctly I matched the time code that is indicated above every section of the VTT file (see the attachment in my initial post above), with the timecode in my video editing software for the spot in the video at which point I want the subtitle wording to appear.

That's only if you have one video clip and one VTT file though, starting at the same time code so that they match all the way through.  I eventually ended up chopping up my overall video into smaller independent pieces, such that each would need its own VTT file.  As I said, I ultimately didn't go through with the subtitles exercise, but I would imagine that it would be necessary to chop the VTT file up into several files as well (one for each video segment, each containing just that segment's wording), and then editing the timestamp in each of those VTT files to begin at 00:00:00:00 or similar.