$mp4 - Images are also blocked in Firefox

[realodix]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

When I use $mp4, the image is also blocked

A specific URL where the issue occurs.

https://github.blog/2023-03-28-github-galaxy-2023-empower-developer-teams-with-a-new-developer-experience/

Steps to Reproduce

1. Add ||github.blog/wp-content/uploads/$mp4
2. Open https://github.blog/2023-03-28-github-galaxy-2023-empower-developer-teams-with-a-new-developer-experience/

Expected behavior

According to the documentation in https://github.com/gorhill/uBlock/wiki/Static-filter-syntax#mp4

It should behave similarly to ||github.blog/wp-content/uploads/$redirect-rule=noopmp4-1s where images are not blocked too

Actual behavior

||github.blog/wp-content/uploads/$mp4, the image is blocked too

uBO version

1.48.0

Browser name and version

Firefox Developer 112

Operating System and version

Windows 10