HELP! DSL Wifi status is up, network is visible for connection, but devices will not connect
We have an AT&T DSL modem we've been using for years, but yesterday all our devices using wifi (3X iPhones, 3X iPads, and 2X laptops,) stopped connecting to it. The devices can still see our wifi network, the password nor any settings have changed. The devices just stopped being connected and cannot reconnect to the network by wifi.
Our desktop computers connected to the network by ethernet still work and have internet access, and our wired phones still work. It's only our wifi connected devices that are perpetually 'connecting' but never connect.
We tried restarting wifi and all modem services through the AT&T Gateway UI multiple times, and also tried hard booting the modem multiple times by unplugging/plugging in the modem. Gateway seems to indicate that wifi is active and working, and the modem's wifi light has a faint flickering green light (indicating small activity from some device I guess.)
ATM, we're at a loss and considering buying a compatible third party modem, but a new modem doesn't guarantee that it will solve this problem. Does anybody here know what could be wrong or have suggestions we can try?
Thanks in advance for any helpful information.