I’d guess that you have a harness issue that vibrated loose. Check the connections to the key switch and the end that goes to the engine. You’re looking for obvious loose connections and/or pins in the connectors that are not firmly seated in the plug. I imagine you used the key to start it? Or is it a pull start engine? Take it to an Evinrude service shop or your dealer for warranty work as any other service center does not have the diagnostics or the factory support that an Evinrude service center does.