CEA-608 captions get cropped when using the native text displayer

[simonlary]

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

If the problem is related to FairPlay, have you read the tutorial?
Not related to Fairplay

What version of Shaka Player are you using?
Every version since 4.11.0, including the latest 4.15.2.
Version 4.10.26 works correctly.

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

Are you using the demo app or your own custom app?
Both

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

What browser and OS are you using?
Reproed with the demo player on Chrome 137.0.7151.103 on macOS 15.5, but we have the problem in our app on Chromecast on all the Chromecast devices we tried (Chromecast v2, Chromecast v3, Google Streamer, etc.)

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

What are the manifest and license server URIs?
Sent by email

What configuration are you using? What is the output of player.getNonDefaultConfiguration()?
Default config of the demo player with "Shaka Controls" disabled

What did you do?

• Disable "Shaka Control" in the demo player
• Use the demo app with the provided stream URL (sent by email)
• Enable the captions

What did you expect to happen?
The stream should play with the captions in the right places

What actually happened?
The CEA-608 captions are displayed incorrectly. They are often cropped and sometimes multiple lines are overlapping.

(No image in the screenshot because of DRM)