Noob with slicing issue...

I created a spoiler for my car that I plane cut to fit into my creality cr-10 s5. My model was hollow with the bottom being open which I guess wouldn't work so I used prusaslicer to fill in the open side. My issue now is that when I see the object on 3d editor view it looks correct but when I slice and click preview it looks like its only printing one layer. I thought it was just me so I tried to print anyway and it printed a small layer and then that was it. I'm a noob at this so I don't even know what to even look into regarding trying to troubleshoot this. Can anyone help? I uploaded one of the files in case someone wanted to look at it. Thanks in advance!