User scripts related to HTML5 video player are not supported.

[hsp1020]

https://greasyfork.org/en/scripts/381682-html5%E8%A7%86%E9%A2%91%E6%92%AD%E6%94%BE%E5%99%A8%E5%A2%9E%E5%BC%BA%E8%84%9A%E6%9C%AC

https://greasyfork.org/en/scripts/405897-%E8%A7%A6%E6%91%B8%E5%B1%8F%E8%A7%86%E9%A2%91%E4%BC%98%E5%8C%96

https://greasyfork.org/en/scripts/375806-%E6%89%8B%E6%9C%BA%E6%B5%8F%E8%A7%88%E5%99%A8%E8%A7%A6%E6%91%B8%E6%89%8B%E5%8A%BF
(video gesture feature not supported)

https://immersivetranslate.com/en/
(video-subtitle-translate feature not supported)

HTML5 video player-related user scripts don't seem to be currently supported by some sites. (ex: hdtoday.tv, 9Animetv.to)

This does not happen when you install user scripts through Tampermonkey in the Kiwi browser.

[JingMatrix]

Please provide a video page for me to test.
And show me what it should look like if it works properly.
Currently, it seems they don't do anything on YouTube.