Not sure how you region change a phone. Make sure they are set to the country your in and the correct language.
My phone is one I got from kogan online and is either Vietnamese or Indian model.

I think the unable to download profile error is misleading. Make sure that the profile for the phones is setup correctly with the correct authentification id (can't believe they all haven't fixed that nearly 3 years later)

Just looked in the play store it says s5 is not supported anymore. Needs to be s6 or higher.