Small one.
Searching for something Lyrenne can't find used to just say "No results found", which reads like the app is broken. It now tells you why: Lyrenne searches YouTube Music rather than all of YouTube, so general uploads aren't in the catalogue it looks at.
Mostly this clears up confusion around the Videos filter. That filter finds music videos, which is what "video" means on YouTube Music, and it was working correctly all along.
Upgrading
Auto update handles it, or grab the zip below and extract over your existing folder.