After further analysis of my code I managed to find the error. It was on the xaml side, since it used an absolutlayout. It did not allow the SKCanvasView to render correctly.

It was solved by using the SKCanvasView, outside of an absolutlayout. A grid was designed to allow correct rendering.

 <skia:SKCanvasView x:Name="CanvasView" PaintSurface="CanvasView_PaintSurface" 
                       HeightRequest="450"
                       ZIndex="0"/>

The aforementioned code together with the code used from c# works perfectly.