It was correct on my realtors listing, but I cannot say regarding MLS since the error was noticed by a family member on Zillow only. I do know MLS helped handle the issue with Zillow so I have to assume it was wrong in both places.
That makes sense since Zillow is merely an aggregator.
Many years ago, I worked as a software developer for a real estate marketing company where I developed software to import listings from various MLSs into our database to be displayed our agent/broker clients' web sites.
Basically, our package was similar to Zillow in that we only imported the MLS data/photos.