Have to restart and reconnect after each use

At one point connection worked each time. Then I had to reconnect after 3 sessions. Now each time I use the APO, I have to unplug, set four digits, select Wi Fi then enter password. It then says could not connect. Do it all over again. After all the steps, it says cannot connect. Then, just before I throw the phone against the wall, it says it is connected.

How do I get back to the point that it just works session after session?

Yes, it is on the correct band. WiFi is fiber, so band width is not an issue