Steps to reproduce the problem

1. https://aus.social/@[email protected]/115460377710762821
2. click play

Expected behaviour

Youtube video plays.

Actual behaviour

Youtube video errors out.

Detailed description

Mastodon instance

aus.social

Mastodon version

v4.5.0-rc1

Browser name and version

firefox 144

Operating system

Windows 11

Technical details

console-export-2025-10-30_16-25-54.log