Just about every click I make in a tab will open a new tab. For example, logging into Primevideo, when I click login, instead of going to the home page in that same tab, it opens the my homepage in a new tab and the current tab I'm on will stay on the login screen. Watching Youtube videos: when I click on another video, it automatically opens that video in another tab instead of in the same tab. I was reading an article earlier that was multiple pages long. When I would click "next" for the next page, instead of going to the next page in the same tab, it opened a new tab for the next page, and kept that page open. I used to be able to choose if I wanted something open in a new tab by right clicking on it, but now a left click will force a new tab. I have set Firefox to automatically update, so as far as I know I'm on the most updated version, and I'm running it on Windows 10. How do I stop Firefox from opening a new tab with each left click I make?