These are linear hex elements with Full Integration and Keyop(6)=1 for mixed u-P formulation.

Note that this is a quarter model: half the thickness with a symmetry plane at the midsurface and the top half of the sheet with a symmetry plane at the center of the notch slit. The reaction force is half that of a full model due to a model having only half the thickness.

One problem with Hex elements is they can develop an Hourglass deformation mode.  The following 3 slides show it being initiated.

Here is the link to the ANSYS 2023R1 archive.