An add-on such as uBlock Origin blocks ads. You can alter its preferences to allow ads on that site and others if you wish. You can also use its toolbar button to stop javascript which may stop the ads cycling.

Thanks so much for your help. I installed the U Block Origin. It removes the ads but the text still jumps up and down some as the blocker fights the ads. I've gone to using Chrome just to read my local news paper (Rochester Democrat and Chronicle). Chrome is rock stable. Firefox works fine for all other sites.

hello jank,

can you test that webpage via FireFox Private Window mode and then also with FireFox Safe Mode?

Safe mode was just as bad as normal, jumping a full paragraph height. Private mode and Ad-blocked mode were a little better. The text jumps a few lines, like it's making space for a new ad, but then nothing appears. Thanks again.