Digital BW, The Print

Hi.
I'm using the r1800 3pkn +glop approach with Ilford GFS.
I'm struggling getting prints, containing mainly dark tones, to look
good. There is a difference from what I see on screen to what I get on
the print which seems all but impossible to bridge by creating an
adjustment curve in PS.
Everything besides my many dark prints look excellent, but the darker
areas look often look almost posterized and unappealing. Also, with
different lighting the dark areas have dramatically different appearances.

So, is what I am experiencing something which those of you using 3-pkn
is familiar with? Are there ways to solve this? Is there a reason to
change paper perhaps?

thanks for any help

sincerely,
Espen