Q-Criterion not appearing in Contour filter

Hi all!

I have used the gradient function applied to a file.nek5000 dataset to compute the Q-Criterion.

I can visualise the “Q Criterion” visualisation option in the top bar (along with Solid color, pressure, etc).

However, if I click on file.nek5000 and apply a Contour filter, I cannot select “Q-criterion” from the “Contour by” menu in the filter properties.
The only way I manage to obtain the “Q Criterion” voice in the “Contour by” menu is if I apply the Contour filter to the Gradient filter directly.

Is this supposed to be done in this way? Is it correct to apply the Contour filter to the Gradient filter, and not to the file.nek5000 file? And if not, how can I make the “Q Criterion” option appear in the “Contour by” menu?

I am using Paraview 5.11.1.

Thank you in advance, have a nice day!

Lorenzo

please share your data.