Greasy Fork is available in English.
可自由設定影片循環播放，無須轉跳其他網站服務。
< Feedback on Youtube 指定片段循環播放
Might have nothing to do with the script, and more to do with Chrome's Manifest-v3 affecting script managers: https://arstechnica.com/gadgets/2024/08/chromes-manifest-v3-and-its-changes-for-ad-blocking-are-coming-real-soon/
Not working anymore on Chrome, it seems.