Wow, just got rejected by Los Angeles. All they said was,

"Your visa application has been rejected. Please reapply visa, the name on the application is incorrect. Please fill in the name/middle name/surname/suffix or “-“ or spacing, no more no less, exactly as it appears on the travel document /passport."

I went back in and submitted a new application, this time trying to understand what could have gone wrong. At the final step before submitting, it looks like the system randomly deleted my middle name. I went back to the beginning and filled everything in again. At the final step, my middle name was there. I guess that's it. The first time, I guess I thought maybe it was blank there for a reason, because of course I filled in my middle name.

The lesson is to expect glitches and carefully review the boxes before submitting. That's a great way for them to get extra money on more applications.