Hello @spquinn ,
I took a look at your model and made a few adjustments to the BCs. Rather than setting all sides of the outer box to the Atmosphere BC (inlet/outlet), I set 5/6 of them to a free-slip wall, and then just set one to this BC. This will avoid any ambiguity at the corners of the box.
I reset all the numerics back to default and it ran nicely out to 200 iter. You can run with it from here (I shared my project back with you). Partially converged velocity field:
