DANKE, Christiane !!
This solved the problem !!! Thank GOD I had to install only one SP, which turned out to be really cumbersome, as the import wasn't starting and I was getting some ridiculous tp errors. Here is the
solution, in case somebody shall stumble over this too:
cd /usr/sap/trans/bin and execute tp connect SID pf=TP_DOMAIN_SID.PFL
