I suggest using the extension “YouTubeChannel2RssFeed”, with this, you don’t have to manually convert the youtube channel links to RSS feed links.
With YouTubeChannel2RssFeed installed, you can simply use the url: https://www.youtube.com/@somechannel and it will add it as https://www.youtube.com/feeds/videos.xml?channel_id=%7Bid_goes_here%7D.
Edit: Link to extension
I believe what you might be referring to was reported here: https://github.com/civilblur/youlag/issues/2
The workaround was to enable the User JS extension first, and then the User CSS. This order requirement will be fixed in the next update, and the README has been updated.
If the page looks like it is constantly loading, you can open up the inspect mode on your browser, then add the CSS class youlag-loaded to the body element. This will allow you to manually exit out of the loading state.
Please note that there is nothing in the Youlag extension that can or will inherently corrupt your FreshRSS instance, so all your data is safe.
Edit 2025-02-23:
Please use the latest release, which is v3.0.4 as of writing.
Since I don’t use a TV myself, I have not looked into this scenario unfortunately.
Sorry about that, I’ve included the fix in the latest release, and instructions on how to bypass the loading screen in the release notes:
https://github.com/civilblur/youlag/releases/tag/v3.0.4
Here in an excerpt from the release note:
Edit: Fixed typo on CSS class name