I recently updated from an older version of OS X to 10.15.5. This has happened numerous times and I am trying to figure out if there is something I am doing to cause it. I am on a Mac PowerBook Pro. I can have several Firefox windows open and something I do by moving my "mouse" (the trackpad) from right to left deletes all open windows and resets to my home page, essentially like I have just opened the app. Firefox doesn't quit or anything, it just wipes out all open windows which is very annoying. As it is a trackpad and I am moving my finger across, I am wondering if my thumb is doing something inadvertantly. Is there a "movement" or something that is causing this? Any help or suggestions would be most appreciated.