[Bug]: YouTube shortcut not working

[cherrynoize]

Pre-Submission Checklist

• [X] I have checked the existing/closed issues to ensure this issue has not already been reported.
• [X] I am using the latest supported version of the browser.
• [X] I have tried disabling all browser extensions/add-ons to rule out interference from these.
• [X] I have tried clearing the browser cache and cookies.
• [X] I have checked with a new profile and the issue still occurs.
• [X] I have provided detailed step-by-step instructions on how to reproduce the issue.
• [X] I have included relevant screenshots or console outputs.
• [X] I have checked that this problem is not occurring in the latest version of Firefox ESR.
• [X] This issue is specific to this browser and does not occur in other browsers.

Bug Summary

The + shortcut for the subtitles size on YouTube doesn't work under Floorp.

• works, and I've verified this with addons disabled. Also it is working using Edge.

Reproduction Steps

1. Focus the video
2. Activate subtitles
3. Press "-" to decrease font size
4. Press "+"

Expected Behavior

Increased font size

Actual Behavior

Nope

Screenshots

Browser Version

Mozilla Floorp 11.19.1

Operating System

Windows 11/Arch Linux

Additional Context

No response