The issue has been solved
related_videos
is always empty.
I'm using the latest version of ytdl-core, 0.29.5.
At some point earlier today, YouTube changed something on their end that means ytdl-core fails to find the data. This also affects the Invidious project in exactly the same way.
Related video data is still available in the HTML, so just changing where you look for it should be enough to fix this.

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posted by issuehunt-app[bot] over 5 years ago
For me related_videos is always empty. Should I open a new bug? Can someone confirm?
By the way, a test could be added that checks for related_videos results.
posted by flaviotordini about 4 years ago