Sounds like the fill/grind ratio.
On different equipment we were grinding on 15 and filling really high.
The wife went on a course and came home and blew some beans on practising, and now we are on 7 on the grinder but 2mm less fill after tamping.
The extraction is way way better and hitting the 25 second rule, turning to drips half way to cup etc. Remarkable improvement.
We get a dry puck either way and use an Espro tamper which is set at 30lb (13.6 ish kg) so I would look at the combo of the other two.