This might be a stretch but I recently started having a similar issue every once in a while. I fix it by fully restarting both my pc and my router.
Edit: I think this is actually something weird going on with my router because I have another completely unrelated issue where I have to restart the router to clean its cache to get some of my ssh sessions to work. That's completely unrelated to faf, but might have a similar cause with whatever my router is doing.