Recently I bought a new Mac, and used my external TimeMachine backup drive to put all my data on the new MacBook Air. Since then, Firefox is having trouble with certain sites. On Patreon.com, most data won't load - I just get their swirling "wait" pattern forever. On Libsyn.com, the podcast description field for when I'm posting a new podcast episode fails to appear - the label "Description" is there, but no field. Also, if I use Facebook Messenger, to talk to someone, inevitably about five minutes into the call, I'm told that there's a lot of noise on the call, or a lot of echo on my voice, or they can't hear me at all. For me, the connection is fine, but the other person experiences this. It's not a mic problem -- happens regardless of which mic I'm using, and other options like Skype don't do this, just Facebook. Since all of these sites function fine in other browsers, I'm assuming something got slightly messed up in Firefox during the migration to the new Mac. What can I do to iron this out?