EDIT: I managed to get it to work, starting from sratch. But i still don't understand why it won't work in another place. I'll check again later. I close the question.
i tried to implement what is described in this blog article and in this technote in a xamarin.ios project without success:
I used the same appearance hierarchy and constraints, but i keep having the error 'Unable to simultaneously satisfy constraints'. The problem relies in the 'Container View' whose constraints can not be set to 0 right/bottom spaces of the scrollview without triggering the error. But if these constraints are removed, the 'Container View' has no width/height and the scrollview does't scroll.
Anyone has a working demo project from this blog post ?