Melitta Caffeo Ci E970-103 Coffee too aqueous

Hello,

I bought a coffee machine (Melitta Caffeo Ci e970-103) and dismantled it first and cleaned it meticulously and put it back together again. Afterwards I went through all the cleaning programs.

Now for my problem:

Unfortunately I have one spring left after the assembly, it is very small (approx. 5 mm wide and approx. 10 mm long) and the grind adjustment is stepless. I'm assuming there's a connection. Can you help me where this belongs exactly?

The main problem is that the machine no longer presses pads and the coffee therefore tastes very lax.
What
could be the reason?
I have already read myself in forums, but unfortunately found no posts, should I have overlooked a post, I like to point it out.
For the
Zusmambau I
used
the komtra videos on Youtube
.
Mfg and many thanks Tim