Closed Caption Icon does not appear

I can confirm that 3 years later and using Storyline 360, this is at least sometimes still a problem.

I am happy to send along a file if I can do so privately as I cannot attach something publicly here, but even after creating a brand new text-to-speech file and ensuring CC is checked (and added into the player), it is not showing as even an option to turn on or off in the player once published.