These tolerances seem unrealistically tight:

`define CURRENT_ABSTOL 1e-30
`define CURRENT_RELTOL 1e-12
`define VOLTAGE_ABSTOL 1e-30
 

In double-precision arithmetic, one usually gets about 15 digits of precision. If you have a reltol of 1e-12, if your currents were order of magnitude 1A (for example), you are asking them to sum to zero within 1pA, even though there is numerical noise at the 1fA level in each of them.