..cowgirlinthesand:
There are other factors involved; Firefox uses different certificates.
Mozilla has custom versions for most operating systems out there.
(Some aspects of security & codes are not shared among browsers.)
Same with Brave; in several ways, they're ahead of the curve.
Versions of 'Mozilla Firefox' across range of supported products
offer longer-spans of support; and is driven by non-profit status.
Most of their rationale is published on product's 'splash screen'
and can be read on main pages; prior to specific version builds.
There was a lot going on, with browsers & security certificates, after 22/27/30 Sept '21.
Safari/Mac and its 'associated webkit' had some issues; other browsers had a few too.
You must update your Mac OS version to a newer one to get a newer version of Safari.
Certain problems affected many Apple Safari-based browser webkit security/certificates.
Topic in general comes up in search engine needs fine tuned to show certain details:
https://duckduckgo.com/?t=ffab&q=how+to+update+browser+certificate+security+authority+macOS&ia=web
Good luck & happy trails!🌻🌤🌿🐢