To restore animated thumbnail previews. Requires inline video previews to be disabled in your YouTube user settings (Go to https://www.youtube.com/account_playback and set "video previews" to disabled). Not Greasemonkey compatible. v5 Add new method for getting an_webp GIF-style thumbs when not available in YT's new homepage UI or subscription page UI.
< Restore animated thumbnail previews - youtube.comについてのフィードバック
It seems the latest addition I made doesn't work on Chrome+Tampermonkey for some reason. So I've rolled that back so you should be ok with upgrading to v5.8 to fix.
Yes, that fixed it, thank you so much!
The script no longer works sadly :/