Have you read the FAQ and checked for duplicate open issues?
YES

What version of Shaka Player are you using?
v4.3.4-uncompiled

Can you reproduce the issue with our latest release version?
YES

Can you reproduce the issue with the latest code from main?

Are you using the demo app or your own custom app?
Demo app shaka-player-demo.appspot.com

If custom app, can you reproduce the issue using our demo app?

What browser and OS are you using?
Chrome Version 109.0.5414.120 (Official Build) (64-bit) on Win11

For embedded devices (smart TVs, etc.), what model and firmware version are you using?

What are the manifest and license server URIs?

What configuration are you using? What is the output of player.getConfiguration()?

Demo app shaka-player-demo.appspot.com

What did you do?

Played a HLS video with the following cue in the webvtt file:
10:00:00.000 --> 10:00:04.000 line:90%,end position:10%,line-left align:start
<u>First line is underlined</u> and left positioned.
<i>Second line is italic</i> and left positioned.

What did you expect to happen?
The vertical line spacing between the two text lines should be the same as when there are no formatting tags present in the cue. There should be no additional transparent space between the text lines when any formatting tags are present.

What actually happened?

As soon as there is a formatting tag present in the cue like <i>, <u>, <b>, <c.lime> or similar, there is an additional line spacing between the text lines. There is a transparent space between the lines.

When there are no formatting tags present in the cue, the text lines are displayed without additional line spacing. The box is contiguous without a transparent space between the lines.

Without tags:

When any tag is present in the cue (additional transparent space between the lines);