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I have a Logitech MX Anywhere 2. Whatever I try it seems impossible to disable the "back/forwards" side buttons on it. I've gone into the Logitech software for it and made sure they are set to "None" on both, but they still are hot. I've even tried installing an extension to my browser called BackStop and not even that has been able to disable these devil spawns. Everything as far as I can see is set to not use these buttons, but they are still doing their thing regardless of the settings. Which is more then mildly annoying to me as I'm left handed, and I don't have count of how often I've been in the middle of something and suddenly the browser jumps back so I lose everything.