All our Firefox browsers (version 99.*, Windows 10 Pro or Enterprise) in the company need around 20 seconds to load a web page when first opened. All other browser functions work fluently from the beginning. Also the slowness only happens after opening and not during further use. Which Firefox is refusing to load I can open other tabs and e.g. do a Google search and then the "slowness timer" starts again (independently if the first tab is closed or stays open) and refuses to do anything on that tab. Once the slownedd period is over all tabs are loaded and no further problem occurs. This issue occurs only when the GPO "URL for Home Page" is applied. But this page is reachable and when Firefox is working it loads within milliseconds. For testing I created a new profile and on the first startup the problem already occurs. And all other startups too. When temporarily removing this one GPO entry it immediately works again fluently. It also doesn't matter what I set as home page (company internal website or some random web page); it is always slow once this setting is in place.