Closed captions don't fade with time

The bug

In Java Edition, subtitles/closed captions appear white, then fade to gray before disappearing. This visually indicates how recently the sound occurred, and when the caption is about to disappear from the screen. In Bedrock, this doesn’t happen.

How to reproduce

1. Enable closed captions

2. Break a block

Expected behavior

Caption should appear white, then fade to gray then disappear

Observed behavior

Caption remains white, then abruptly disappears