Unable to register for an azure account because your system does not know how to deal with APO AE addresses for deployed military....
Unable to register for an Azure account because the system does not know what to do with an APO AE address and says my state of AE is invalid, this makes it impossible for military at APO AE addresses impossible to sign up.
I had the same issue. Opened a ticket in the support system and after about a week the "support engineer" came back with the answer this behavior is "by design" and told me to "use a credit card that is billed to the country your services are billed to".
Seems odd that by design you would add AA, AE, and AP to your States drop down menu just to not accept them on your validation callback. Seems a lot more like a bug in your validation.