I’m afraid it is not possible from the description and looking at a couple of screenshots to tell what might be going wrong. There is some kind of issue with the surround. The dome and waveguide look reasonable but letting 3D CAD programs make meshes for BEM does not normally work. Not using symmetry and trying to simulate a very large system as a first try is likely to be counterproductive. My advice would be to start small with the waveguide until you have validated what you have and for the 6 inch and larger driver in a big baffle Vituix will give a pretty reasonable answer with its diffraction simulator much faster and easier.
