Element overlapping unit cell in frequency selective surface

I am new to HFSS and am trying to model a frequency selective surface of tightly packed tripoles in an equilateral triangular (hexagonal) grid. I set up a trapezoidal unit cell with master/slave boundaries and floquet ports on each end and as long as the leg lengths are short enough to stay within the trapezoidal cell, there are no problems and the analysis runs fine. But as soon as the legs intersect the unit cell walls I get an error.
I am running ANSYS Electromagnetics Suite 19.2.0
Any suggestions on how to overcome this so that the elements may be packed tightly?

For whatever reason, your structure is not identically mirrored along the periodic boundaries. Can you post a picture, or the simulation file?

Here is the simple case that I am trying to analyze.

I can't really tell what's going on in the picture; but if the rhombus is your unit-cell boundaries, then it appears that your structure extends out of the boundaries, which it shouldn't.

Yes. That is precisely the question that I am asking. Is it possible to let the structure extend beyond the unit cell? I think that I see how to generate a unit cell for tightly packed tripoles on a single layer, but I have other cases that I?d like to analyze that have multiple layers with overlapping periodic structures and I don?t see how to make a unit cell without allowing the structure to extend beyond the unit cell boundary.

No the unit-cell components may not extend out of the boundary. If you want overlapping components, you need to insert these manually by mirroring them on the opposite side of the unit cell.

What I would do in this case is duplicate your unit-cell outwards such that you have an array of 5 unit cells, with the already existing one in the center. Then, use HFSS's intersect command to intersect the domain with all 5 unit cells.