Weird bug when changing from prepare to preview in Cura 5

[sft3dprint 0]

I was slicing this simple wall box and the view in prepare looks correct but when I go to preview you can see that the box floor has been raised.  

 

I`m just now printing it to see if it comes out correct.  

 

Any thoughts on this?  

 

Been using Cura 5 for a while now and this is a new one for us. 

[ahoeben 1,850]

10 hours ago, sft3dprint said:

I`m just now printing it to see if it comes out correct.  

It won't.

 

Without a project file (File -> Save project...) it is hard to be sure, but there are generally two possible causes for this: Either your model has issues and needs to be repaired, or your settings are telling Cura to do this.

 

One setting that can cause this is the "remove all holes" setting.

 

If you load the same model into 3D Builder, does it say that "One or more models are invalidly defined" and offer to fix it?