CST - LF-FD coaxial structure unphysical results

I'm still on getting hands on CST Studios LF solver by modelling a simple coaxial structure. So far I validated the calculation of skin depth, inductance and ohmic resistance. In order to claculate the capacitance I switched the model to an opened pice of coaxial cable. It's like a cylinder capacitor filled with air. I applied four current paths symmetrically with 0,25 nA each. Thus I expact a voltage of about 0,5V between inner and outer conductor. With LF-FD Fullwave solver at 10 Hz I get 1,9 kV instead! On the other hand the E-field is about 10^3 times weaker than analytically calculated. Thus the calculated capacitance is much to small. Somethings in this model is totally wrong. But I can't get it. May anybody could help me?
Community members told me in an other post to try pRLC solver. Actually I don't about this solver and hardly found any documentation about it. May there is some information (PDF or Tutorials) I can study?
Thanks in advance!

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