IP simulation with Vivado
I was using a module that was not supported by Vivado. Apparently the machine I was working on had an old ISE installation and the cores got mixed up. That's why some modules were impossible to simulate and others worked perfectly from the get go. 

I think it should've worked, but maybe the licenses didn't match or the sources were unavailable for Vivado. I don't think it's a licensing problem because Vivado didn't throw any license errors (I forced a licensing error by simulating the AXI BFM and Vivado told me I didn't have the license)