I'm running Firefox v74.0 on Windows 10 v1903 with all the latest security updates. My homepage is www.yahoo.com. When I start Firefox by double-clicking the icon on my desktop it opens the homepage correctly. When I start it by clicking the Firefox icon on my taskbar, the main window of Firefox remains blank and it won't open the homepage until I click the homepage icon in the upper left of the Firefox screen. I have already deleted the icon on the taskbar and replaced it by dragging the icon from the desktop back to the taskbar.