Istio 1.6.0 - traffic seems to bypass sidecar

Hi all,
I have a Istio 1.6.0 fresh install.
I deployed the bookinfo demo application; but I’m experiencing a strange behaviour: in Kiali I see that some traffic goes directly from the ingressgateway to the productpage service bypassing the sidecar proxy (see image below)
The other traffic goes normally through the sidecar proxy

I’m almost sure tha this didn’t happened in Istio 1.4 and 1.5

I’m doing something wrong?