app.NonReleaseVersion not showing on some Mac's

i am using str(app.NonReleaseVersion) to show the version number of my product. However it seems that out of 10 people 4 people get a blank returned. I’ve not found out why yet, is anyone else seeing this?

this value is read at runtime from info.plist in a Mac app.
So if you use AppWrapper or similar, they may make the version number shorter there.

You can disable this feature in AppWrapper using this checkbox: