OK! So that worked...What I found out was....mine also exhibits this issue. As you can see I clamped the two pieces flat to the MFT. The board was just cut in half for the test so it was flat. I referenced the base on the MFT so that takes the board out of the question.
After the mortice I placed a domino in the cuts and slid the two boards together. The natural fit has them shooting away from each other at a slight angle. I have attached a few pictures showing this. If the boards are allowed to lay flat...the weight of the board will allow them to lay flat together.
After the mortice I placed a domino in the cuts and slid the two boards together. The natural fit has them shooting away from each other at a slight angle. I have attached a few pictures showing this. If the boards are allowed to lay flat...the weight of the board will allow them to lay flat together.