current distribution conductor

When I design a coaxial connector in CST's MWstudio,I interest in the outer conductor's current distribution because there some area not regular.but MWstudio couldn't give me outer conductor current distribution,because it's background material is PEC,ther is only inner conductor's current can be seen.I have tried to use a loss metal brick to contain the connector,but when simulation,it has error.software said there was unstable.So what can I do?The inner conductor's current can show up outer conductor's current?I know in theory they must symmetric.The other thing,use loss metal aginst PEC as outer conductor wil influence result how much?
Thanks!