Diagnosis
The opener's Wi-Fi radio doesn't support modern router settings. It likely can't connect to a 5GHz network or a combined 2.4/5GHz SSID.
How to Fix It
Log into your router. Create a separate 2.4GHz Wi-Fi network with a simple name and password. No special characters. Disable any "band steering" or "smart connect" features that combine bands. Bring your phone close to the opener. Connect your phone to that new 2.4GHz network, then run the MyQ app setup again.
If That Didn't Work
The control panel antenna inside the motor unit might be loose. Remove the light cover. Check the small white Wi-Fi antenna wire connected to the logic board. Ensure it's plugged in firmly.
Heads Up
The B970T opener cannot connect to enterprise-grade or public Wi-Fi that requires a login portal. It needs a standard home network.