Dear @damir ,
please have a look at this recent post: CVMFS setup failing with awk: symbol lookup error
In a nutshell: The LXPLUS nodes were moved from CC7 to EL9. Sadly, we started deploying EL9 builds to CVMFS only from v3.0.3 on, but sourcing these will solve your issue.
It looks like if you require v3.0.0, you can logon to lxplus7.cern.ch instead, but for patch releases (e.g. 3.0.0 → 3.0.3), all simulation results are verified to stay untouched.
Best
Paul