You need to turn on the option "useprobes" (spectre -h options). In OCEAN:

Code:

option('useprobes "yes") 

This tells spectre to put an iprobe in series with all devices, and measure the current through that. Spectre cannot normally measure frequency domain device currents (in ac simulations too) without using useprobes.

You should be cautious of using useprobes (and subcktprobelvl) for big circuits because it can add a large number of iprobe components (check the circuit inventory in the simulator output) which can lead to increased memory usage and slower simulations. Just be careful, that's all...
There are plans to solve (or at least minimise) this requirement for iprobe insertion in an upcoming release.

Best Regards,

Andrew.