In Duolingo you can turn on/off the sound settings which include 'motivational' noises when you answer correctly. I find them annoying so have them off. I've been using Duolingo and Firefox together for years, no problem, then a couple of months ago these sound settings became ineffective i.e. permanently on even if turned off in Duolingo. I thought the problem was a bug in Duolingo until I loaded it from Microsoft Edge and there was no problem. The settings turned on and off. I'd prefer to carry on as I was before and just use Firefox. How can I fix this?