Why are subtitles not showing on my iPhone 16 Pro Max Full screen mode?

When go into full-screen mode, subtitles disappear. Tested in iPhone 16 pro max with iOS 18.1 both on Safari and Chrome and multiple websites including YouTube. Same problem from 2021 as described below. It’s unbelievable this problem has still not been fixed after 4 years…

Subtitles disappear in fullscreen - Apple Community

[Re-Titled by Moderator]