Incorrect shading

[max]

Hello, I tried this software maybe year or two ago, tried it again now, and seems I still have shading issues with imported models. I've checked and this impacts not only rendering but calculations also I guess. Is there workaround or fix? I have crazy results with this glitch. I don't know how to explain this, like shadow casts inside of object on backface and then inverts from other side at some angles.
Seems there are no issues with inbuilt geometry, but even simplest box imported from 3ds max (3ds obj) gives headache. I've attached my 3ds model.
And unfortunately this making this software unusable for me. Standard approach is to draw blueprint of walls in acad, refine it in 3d software, import. PVSOL just can't create more or less complicated geometry of roof.
And last two screenshots are example of incorrect shading result with imported geometry and inbuilt geometry walls. This looks like minor glitch in import module because native geometry works just fine, and I hope it can be fixed (or it will be fixed), my geometry is really simple here

single_model_sliced.3ds

[hotline_oh]

Hello,

Thank you for your inquiry.

Please send your project file (*.pvprj) to hotline@valentin-software.com so that we can take a closer look at it.