This is working as expected on UWP and iOS. On Android the text is centered, however it's the container that is left aligned.
To confirm this is the case, I have set the HorizontalAlignment of the Label to End, and this screenshot shows the result at runtime on all 3 platforms. As you can see, by observing the red background, the parent container is left aligned on Android.
Unfortunately, I don't have a workaround for you because there is no access to the native control's container from the current XamarinForms API.
Lance | Tech Support Engineer, Sr.
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