Can you try the wired connection? Regarding ComboFix, there has been issues where ComboFix disconnects the user from internet but not the you are delineating. It seems that you have the connection and can connect to the internet from time to time. ComboFix usually deletes the settings which makes you unable to connect until restoration. Can you try a router reset and re-installing your Internet Adapter? Make sure that you have all the necessary backup of your login information.