Ah, that makes sense then. I was setting up my new Commander Core XT and noticed something.
Zero RPM doesn't seem to ever turn the fans off, but instead runs them at their lowest RPM. I kind of miss being able to have them completely off but it's not really a big deal since they're essentially silent at that speed anyway. Just threw me off since my Commander Pro's were able to. For reference I'm using the XT's with LL and QL fans.