Any one has faced situation of doping rank in google maps business listing?

Not faced yet but yes heard lot. Maybe it would be the impact of algorithm changed. From my point, better is you will want to request or post in Google webmaster forum or Google places forum. You will get accurate reason from that forum.

still no any.

It may due to some change in Google local listing algorithm update.

in last 4 days my one of the blog ranking drop 50%.