I have encountered a couple of issues with TextTrackCue enter and exit events in Safari: - an enter event is fired if an active cue's startTime or endTime is changed - an exit event is not fired if an active cue's startTime or endTime is changed such that it becomes no longer active. I have documented the details of the tests I've done here: https://docs.google.com/document/d/1uq-wVjY3Lq6J3GLZb246-5smIjECxjZ4VqsY-gnIPek/edit There's a demo page you can use to adjust cue start and end times interactively here: https://waveform.prototyping.bbc.co.uk/cue-events
<rdar://problem/58714274>
This bug is related to: https://bugs.webkit.org/show_bug.cgi?id=103417.
*** This bug has been marked as a duplicate of bug 103417 ***