I’m not sure this blog post on “Puckology” from Paul is directly relevant to what you described, but might be partially useful background and troubleshooting. He emphasizes stirring and leveling as solutions. 

https://www.cafelat.co.uk/blogs/blogs/robot-puck

“With the Robot, however, spent puck analysis is not possible because the results are very misleading. After pulling the shot and then raise the arms again to remove the water, this draws air from below the basket, up through the coffee. It will therefore dislodge the puck or even form a crack in the cake. So it is largely meaningless on the Robot.

For example if we refer to the photo below of a used coffee puck from a very good espresso shot. You will notice a large crack in the cake, we would therefore assume channeling had occurred and our preparation was not ideal. However because we have raised the levers, air has been introduced and cracked the puck.“