I just bought a 400gb micro sd card and installed it in my Xperia XZ. It is recognized immediately and I have no problem using it.
I don't know why Sony Staff gave you the wrong information. The main reason that I don't want to buy any Iphone is that you cannot install micro sd card. I listen to music on my cell phone and I have more than 400 gb of mp3 music. So, it is important that I can expand the capacity of my cell phone with a micro sd card.
Hopefully Sony updates their information and tell their Staff the right information.
The information stated by Sony is still correct, this is the maximum capacity of SD cards tested and provided no loss in functionality or decrease in performance. Theoretically, bigger capacity SD cards will work (as in your case), but performance is not guaranteed.
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