I do not work for Carfax. I can tell you that Carfax does its best to collect information on vehicles. It does not have some special ability to collect information that has not been made available (and that's a lot of stuff due to 50 states and little or no reporting for most things). I can dance around that, but the net of it is that Carfax is not 100% accurate. Advocating for you I would tell you to very carefully inspect a vehicle being sold by Carmax. My company has a relationship with them so I wont say more than that.
If you like you can share the vin via PM and if I have time tomorrow I can see if I know something about that van.
Look in the crevices. Locate the smell. Look under the seats etc. If you have weird title issues that don't add up you have to investigate if someone is trying to dump a salvage. Carmax might not know they bought one.
If the price was a problem I will tell you that any dealer is going to be the same. If you want to do better with used you will need to try a shady small dealer or individual sale. I still think you did the right thing with this van based on color and features when accounting for your intended use and location.