I updated my iOS to Big Sur, and now many emails on Yahoo are displaying content as gobbledygook. Sometimes it's the subject lines, signatures, and email addresses in emails and the threads of forwarded emails. Other times it's the text on home listings or job ads. This isn't happening on my gmail account, or when I access Yahoo through Safari, nor is it happening on my mobile devices. It's specific to the combination of Yahoo/Firefox/Big Sur. Any idea how to fix or when Mozilla might address this bug in an update?

Many thanks, Erika