Who I have the same questioned this topic

That I connect to a Wi-Fi device  it will be stay connected for a few seconds and then drops. I know there's nothing wrong with the Wi-Fi because all my other devices stay connected. But for some reason my galaxy note 4 all of a sudden will not stay connected to any Wi-Fi that  as previously worked for the last six or eight months. I've tried everything I know to do not being the most technologically capable person I need help. LOL thanks