We replaced one wall switch with a door bell button and now the overhead light flashes on when I hit the button, goes off and then the light comes back on when the door is fully open. Before replacing the button, the light would come on and stay on during the door opening operation. When the door is opened with a different second wall switch or with the remote door opener in the car, the light will come on and stay on.
The doorbell switch is not equivalent to the garage door switch it replaced, in some manner that upsets the opener.
If your unasked question is "how to make the light stay on when the door is opening" you need to remove the doorbell switch and replace it with a garage door switch compatible with your opener.