My Firefox browser window has multiple tabs. I would like to be able to close them individually. The tabs do not have the 'x' symbol on them to be able to close them conventionally. I tried to right-click on the individual tabs, but the drop down menu does not have the option available to close the tab either. I tried rebooting the computer but when I open Firefox again, the same tabs are still there rather than opening up a fresh browser window with only the start tab window. I am using Windows 11 with this computer also. Help!!!