I don’t think your station is broken. I had a look at your data and going back to beginning September it didn’t see a single day with enough direct sunlight (which is rather normal in your region). It just slowly depleted to a point it is now empty. Maybe you could try to find a more sunny spot but with winter near, not to sure you’ll find much where you are.
Since the PowerBooster isn’t yet available, could you charge it via for ex this topic or if you are handy maybe make this ??