Thanks for taking the time to confirm the problem.
I guess the good news is that Firefox has less than 8% of the browser market, although I have no idea how that translates into share-of-installed base.
The mystery to me is that all of the mp3 links on other pages work fine, it’s just the links on the one page. Go figure. I sent detailed “feedback” to Mozilla, but I’m not waiting breathlessly for a reply, even less for a fix.
Although I’ve been avoiding it for several years, seemingly the time has come to drop Firefox like a bad habit (as we used to say back in the day). The complication is that all of our Macs—four iMacs and four Mac laptops—run Firefox, connected by a single email address that keeps all their bookmarks, emails, etc. updated. Not looking forward to replacing everything with Chrome, even though its much more sophisticated ecosystem.