LABELS Visibility Range not respected in web scene layer

[Arpa_PiemonteGeoportal_Team]

I have a scene with a simple point feature layer  for geographical place names.

This is labelled in ArcGIS Pro  (2.4 version) with two Label Classes.  Each class  is configured by simple definition queries and visibility ranges toto show only certain and significative labels at different distances/scales

 In Arcgis pro everything works fine BUT WHEN I share the 3d layer as webscene layer (AGOl or our ArcGIS enteprise Portal)  the visibilty range is not respected and all the labels are always visible at all distances.

Any workaround ? if this is an error PLEASE  fix it asap 

cheers
enrico