If you go to the Google Search Console and access your average position metric within the Google Search Analytics tool, you may see a sharp drop in that number. May are noticing that the average position has significantly dropped in the analytics tool while the other metrics have remained flat.
Here is a screen shot from a reader:
Here is a screen shot from a Google Webmaster Help thread (note the green line is the average position):
Google has not confirmed if this is a bug or not, but I suspect it is if so many people are complaining. I personally can replicate this as well on the properties I have access to.
Forum discussion at Google Webmaster Help and Twitter.
Update: This is not a bug, but a feature change to the reports - you can learn more over here.
