maybe perhaps related to this: https://arstechnica.com/security/2025/07/browser-extensions-turn-nearly-1-million-browsers-into-website-scraping-bots/
the affected addons list only mentions jiffyreader for chrome (or some addon masquerading as actual jiffy reader). Could be Mozilla found the addon doing something it shouldn't?
edit: in jiffy reader's github: https://github.com/ansh/jiffyreader.com/issues/342