It's possible that the rollers that suck the disc in have become dislodged. I made a video about that for the previous versions of PS4 but have not made one about this version yet. I'm assuming it's still under warranty so it's best to send it in to Sony for repairs.
You can see the video [https://www.youtube.com/watch?v=wqOhiiIbDb8|here] if you'd like to know the general idea of the cause of the problem.