App requires version not out yet

I am trying to download some new apps to my MacBook Air but it won't let me install any of them. I get an error saying "(null) can't be installed because it requires version 10.14 or later".

High Sierra's latest version is 10.13.6 as far as I can tell. There are no updates available in Software Update.

Is this an error on Apple's part? Any way around it? Or should I time travel?