"Shorts" is a special kind of videos on youtube, and opening them bring you to a specific player that you can't view in fullscreen. This extension redirects you to a normal youtube video player, and solves this problem.
Source code:
github

Install

• License: BSD 2-Clause "Simplified" License
• Weekly downloads: 1
• Average daily users: 14
• Rating: 5/5 of 1 ratings
• Created: 2022-03-31 14:13:39
• Last updated: 2022-04-01 14:31:28
• Homepage:
• Support site and email
• Orig: https://addons.mozilla.org/en-US/firefox/addon/yt-shorts-to-video/
• API: {e80f978f-2d69-410b-9e92-2c2be5e9f4d5}