Just wanted to do a quick follow-up on #8519, the timeout did seem to resolve the issue, but that was true only for the default text-track, if it is not showing by default it will never be visible.

See https://jsfiddle.net/tsish/5quhv8j3/

AFAIK the only way to make Safari behave currently is to disable nativeTextTracks

https://jsfiddle.net/z3nbxo92/