Sounds very similar to my experience.
The EM0480 was fine while I was using a Cafe Crema, but when I upgraded to the Silvia, I had a lot of problems producing consistent pours. When it worked well, the combination was great but too often, I threw away gushers and chokers. I bought an old Mazzer Super Jolly, fitted new burrs and have been very happy with the results. You still have to adjust the grind for different beans and also as beans get older, but it is remarkably consistent - considering my very basic skills in dosing and tamping. I rarely have to discard any coffee now, once Ive initially dialled it in.
End the frustration and upgrade - you wont regret it!