Galaxy J5 (SM-J500F) wont upgrade from Android 5.1

[Android Central Question]

Hi, I would like to upgrade this phone and from what I have read it can go up to version 6.0.1 (Marshmallow). The phone itself (and the SmartSwitch software both say the phone is up to date on version 5.1

Would anyone know why this won't update or tell me how to force it please?

 

[B. Diddy]

Welcome to Android Central! Did you get the phone directly from a carrier, or was it an unlocked phone? Some variants may not have gotten official Marshmallow updates. SamMobile.com shows that the Hong Kong firmware only goes as high as 5.1.1: https://www.sammobile.com/firmwares/galaxy-j5/SM-J500F/