Hi, I believe it's not something Firefox does by default, and this behavior is rather caused by an add-on or a website. To check if it's caused by an add-on, see [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems]]. To make sure it's not a website causing this, go to Firefox Settings -> Privacy & Security -> (scroll down to) Permissions and click "Settings..." next to Notifications. Look for any suspicious websites in the list that have "Allow" next to them and either select Block or remove them from the list. You can even remove all the allowed websites from the list, as you'll be able to give this permission to them later. Does any of that help?