the "geometry garage" checked all the suspension parts and after confirming that everything is Ok, they have done the geometry.
I have SAVA tyres 225/45/17 (it should be 235/45/17 but I didn't know when I bought them 3 years ago!!!!) and the pressure is 2.2 bar (I don't know in psi!).
I had the same problem (of course much less) even when i bought the tyres. Now is getting worse and worse.
When I'm using winter tyres 195/65/15, the problem is reduced but you can still feel the same phenomenon.
i'm planning this week once again to send to a different suspension specialist and ask for second opinion.
thank you all for your inputs and i'll let you know about the outcome of my issue