KF8 drink settings ?

Hello everyone! I have been playing with my new KF8 machine for a couple hours and I can’t seem to get the sour taste out of the espresso shot. I have adjusted strength, body, temp and drink volume. Grind setting is at third from finest.

I know beans play a big role in the taste as well, but I was wondering how other machines are dialed in and what is working best for you ? Milk drinks are tasting ok, it’s just the espresso shot on its own that tastes a little sour.

Thank you in advance!