Model
https://imgur.com/lGv6MQ2
Slice
https://imgur.com/5Wm01c0
https://imgur.com/ibXTuhX
https://imgur.com/FFKDWZ0
For some reason the slicer will not fill-in a round bar all the way through a model. It wants to put a hole in the last two pieces, even though there is supposed to be a bar.
It happened with this thingaverse: https://www.thingiverse.com/thing:1394419
So, I made my own, and it did the exact same thing. This must be a setting error, because no one else is getting it.