Thank you both for responding so fast


@ Death
tried your method and couldn't get it to work. Thanks though for highlighting the Align tool and I will investigate it further . Somehow in your method you introduced a small offset to the piece . Its now shifted fractionally

@Michael
I added a note to the drawing highlighting a slightly bigger piece to fill in the shallow area as you pointed out. I kind of thought the same , that it didn't like the messy divot.
The full height piece doesn't work . But a .01mm offset bigger piece that I went half height with does ( it also works at full height).