When you have pinned tabs, Firefox no longer opens the first link you click (which starts Firefox). It starts, but without showing you the website from the link. Once Firefox is started, clicking links works as expected. Without pinned tabs, Firefox also opens with the first link as expected. So the problem is definitely the pinned tabs. Steps to Reproduce: # Start Firefox and add a pinned tab. # Quit Firefox # Click on a link in e.g. an e-mail to open Firefox with that website -> Firefox starts (with the pinned tab), but ''without'' opening the website from link you clicked. # Click again on that same link and now the website does open. # Remove the pinned tab and quit Firefox. # Click on the link -> Firefox opens ''with'' the website from the link.