Thanks, so it's up to the web designer to make sure it works as expected, so it's a good advice to use a responsive Javascript framework, or of course B4j technologies.
I was thinking the Anchor properties has something to do with the WebView and scrollbars behavior so unless you point this out I assume thre's a tutorial for this that I never watched. I think the controls can remain fixed on each side of the pane so it probably has nothing to do with if scrollbars becomes visible or not!
I should probably post a new question about this? Anchors is a new topic!