I also have the Alexa binding and the need to reenter my password occurs every few weeks. As this is a known issue, I’m sure there will be a resolution soon. You can follow the progress and see what others are are doing to fix here: https://community.openhab.org/t/released-openhab2-amazon-echo-control-binding-controlling-alexa-from-openhab2/37844?u=h102
