I’m trying to make a simple box as part of a personal project. I’m using Sketchup (probably an odd choice, I admit, but it’s what I’m familiar with) to create the 3D computer model for the box. I’ve made multiple small changed through to the model. In short, I’ve made 5 different versions of this lid, 6 including my current attempt.
For reasons I don’t understand, Bambu Studio, when repairing for non-manifold edges, it ends up wanting to fill in the large cavity as seen in the picture below (the interior of the box) instead of leaving it as is. As stated, I’ve made previous attempts, and it never filled in the cavity. I haven’t touched the cavity from the previous versions, but Bambu Studio suddenly wants to fill it in when repairing the model. I’ve tried splicing the model without repairing it, but for some reason it leaves out bits on some layers that as far as I can tell it shouldn’t have any problem with.
I just don’t understand what’s going on, why Bambu Studio suddenly wants to fill in this cavity it never did before. I’ve imported it as an STL, and OBJ, I’ve even removed and redid the cavity on Sketchup, but no matter what I try, Bambu Studio insists on filling this cavity now. I’m quite certain if I print the piece as intended, I’ll finally have the box completed. Is there an easy fix for this?

