Yea, this is a known behavior. VTK forces the window’s dimensions on the canvas. Unfortunately, there isn’t much you can do right now because this event handler is setup inside the interactor in C++ - vtkWebAssemblyRenderWindowInteractor.cxx#L43
VTK can provide 2 options:
- resize the canvas to window dimensions upon browser resize (current behavior)
- canvas ignores resize events from the browser window. (this is what you need)