Ok, new day with new beans and the shocking fact that I’ve mixed up having the large basket from the single portafilter in the double portafilter. I now used the double portafilter with its correct corresponding basket.
I’m still having a hard time to fill it with 18g - i’ve ended filling it up with 15-16g max.
I’m having around 8 bars now, when using “mid-espresso-level-grind”, but the water is running a bit too slow. With the same amount of beans and a bit coarser powder the output speed is fine, but around 7 to 8 bars and 30 seconds extraction time.
Much better now, time for fine tuning :-)