Can somebody help please I'm losing my mind!

[Toasty]

I'm trying to design a box, a jewellery box to be precise and I'm having a lot of trouble with the top piece (lid) The model seems okay, I drag the stl into cura, looks fine still, then when I slice, part of the hinge piece is missing. The bottom didn't have this issue and both bottom and top pieces are identical other than where the hinge is. I'm using Sketchup to model this and I feel like I've tried everything, I can't get it to work. I've included the stl file to have a look at. If it makes any difference I'm using Sketchup web app and Elegoo Cura 4.8.0

I have since found a work around for this, if anyone else has this problem.

I separated the box lid from the hinge piece, saved them both as separate projects, then I imported them both as components into a new project, put them back together and grouped it all, seems to work but Sketchup isn't the most consistent program so it might not work next time.