URL: https://9anime.to/watch/jujutsu-kaisen.32n8/ep-1

Browser / Version: Firefox Nightly 95
Operating System: Android 10 (Oneplus 5)
Tested Another Browser: Yes Chrome

Problem type: Site is not usable
Description: Buttons or links not working
Steps to Reproduce:
Almost all custom video players are broken on mobile Firefox, only the native one (HTML5 video-tag) works as intended.

I am using a Oneplus 5 running Android 10 (stock firmware, OxygenOS 10.0.1) and Firefox Nightly 95 with uBlock Origin. All of these players work without any problems on Chromium-based browsers (in my case Brave 1.31.87 to avoid ads).

The streaming site I linked is a good example as it has custom players from various websites for the same video. Here is a list on what doesn't work for each player:

Vidstream & MyCloud & Streamtape:

• Skipping along the timeline doesn't work, doesn't recognize touches
• Fullscreen doesn't work. Clicking the fullscreen button (or double-tapping) hides the status bar and displays Firefox' "Starting Fullscreen" message but the video stays small and doesn't actually maximize

VideoVard:

• Same problems as Vidstream but in addition, clicking the initial large centered play button doesn't work. You have to click around it to start playback. In Chromium, clicking the large button works after a few clicks.

Mp4upload:

• The play button doesn't work, you cannot even start the video.

View the screenshot

From webcompat.com with ❤️