IMac Display Issue

Hi:

I have an I-Mac which 27" with 5K Display, which I bought in Dec-2015. Late last year (2016) I started to experience display related issues only when I shut down my I-Mac (image below), not ever time but three or four time a week. I also went to Genius Bar first in Dec-2016 and they changed the Logic Board, 4.0GHz, Quad Core, 2GB, i7, afterwards the problem persisted. I went to Apple Genius bar second time in Jan-2017 and they again changed the Logic Board, 4.0GHz, Quad Core, 2GB, i7 and Display, Retina, 27” iMac. Now I am having the same issue again and before I go to Apple again I want to check if someone in the community have the same display issue while shutting down.