This issue may be caused by either a simple glitch or, in most cases, a system upgrade that causes the computer in question to start turning its WiFi adapter off, and thus requiring it to be woken up following every shutdown or restart, in order to save power. Such users have reported that their computers only connect to WiFi networks they already remember and should connect automatically to when they either manually connect to them from their computer’s WiFi menu or, in some cases, press the hardware WiFi button on their laptop.
Many Windows 10 users from all across the globe are complaining of their Windows 10 computers not connecting to saved WiFi networks automatically even though they have made sure that the Connect automatically option for those networks has been enabled.