Mesh appears differently after exporting

I just started using Blender a few weeks ago and decided to try to make something a little more in depth with the intention of 3D printing it. So far I’ve printed part of the project without an issue, but when I came across this part I noticed a significant issue.

The first image is from Blender, and is how the part is supposed to appear. (Yes, I noticed the blue faces. They weren’t blue until I tried to fix my issue, and I still had the issue before they were blue.)

The second image is from Cura. As you can see, the middle does some weird stuff and isn’t anything like what its supposed to be. 3D Builder, which I used to use for basic stuff, showed the same issues.

I’ve tried recalculating outside faces in Blender as well as exporting in various other formats. (Ideally .stl) I’ve also tried using Cura’s mesh fixes.

Is there anything else I can do to try to fix this, or is there a more proper way for me to fix this?

Thanks!