IterableInAppMessage createdAt is null despite it is tagged as NonNull

[allo86A]

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We recently released an update to our app with some code to validate that an in-app message has been created after a cutoff date, before showing it to the user. That field, createdAt, is annotated as NonNull in IterableInAppMessage class, but we noticed that some of our users are getting a crash because that field is null.

The validation we have is simple: message.createdAt.after(calendar.time) where calendar.time is our cutoff date, and the error trace we see for some of our users is: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.Date.after(java.util.Date)' on a null object reference

Is it expected to have a null createdAt?