AFAIK its a normal message we all get and nothing to be concerned about.
If you see here, someone asked on keybase and was told its not an issue.
Edit.
There should be apx 4608 blocks per day, so you are in the correct number region.
I cant be sure, but i believe it just means you got the challenge and thats a good thing, and you wont farm ( win ) every block, so most will say not farmed by us.