Center popup horizontally with Rectangle structure

Hello,

I'am trying to center horizontally a popup with (x and y) position with a rectangle structure : https://docs.microsoft.com/en-us/dotnet/api/xamarin.forms.rectangle?view=xamarin-forms

I tried this : x -> (rectangle.center.x - popup.width/2) ; y -> (rectangle.center.y - popup.height/2)

The x and y point coordinates represent the bottom left corner of the popup.

But the behaviour of my bounds rectangle are weird and don't seems represent the actual size / coordinates of the rectangle.

I use syncfusion popup in this case.