I’ve figured it out. When I imported, I kept the original clip on an external hard drive and had FCPX import and create a proxy but not copy the original media.
When I go to export, Compressor is looking for the original media which I didn’t have connected. Connected it and everything looks great.
That was my mistake but it would help if FCPX warned me like 10.0 versions did that linked files are missing. At least I don’t see any warnings.