Custom editor fonts are blocked on Firefox when using Strict Enhanced Tracking Protection

[louie-github]

Description

When using the Firefox's Enhanced Tracking Protection in its "Strict" level, the Typst web app cannot use custom editor fonts from the system. Trying to specify "JetBrains Mono NL" and inspecting the DevTools console gives the following error:

Request for font "JetBrains Mono NL" blocked at visibility level 2 (requires 3)

Tested on a fresh install of Firefox 135.0.1 (64-bit).

The issue goes away if you switch from Strict to Standard, or if you disable Enhanced Tracking Protection for typst.app.

I believe this is related to Firefox's browser fingerprinting detection.

Reproduction URL

No response

Browsers

Firefox

OS

Windows

[laurmaedje]

I'm not sure we can even do anything about this, since the browser intentionally hides the fonts.