Today when I was checking my baker's performance on TzScan.io (as I do multiple times a day), I got this novelty... "Last Assigned Baking" tells me I have missed it. My baker's performance dropped a tiny little bit for this. But it had never happened before. Nothing has changed in my configuration and I did not have Internet or Power outages recently. What does this mean and how to avoid it in the future? Thanks in advance.