all you have to do is just replace the battery. The console eventually resets itself at midnight, OR… you can put it into the setup mode, and take it back out and that will reset the console.
Flatline? you mean all dashes on the console for direction. I’d contact Davis. I am betting they have their units not built in the US and some bad parts. should last longer than that. Sorry to hear that it is giving you headaches especially since we are both getting into the interesting weather time.