The power probe (wprobe) gives wrong results when used with AC simulations:

see this circuit simulation (circuit taken from here):

note that the overall power values are correct but that the resistor is apparently generating power and has a significant reactive power component...

The issue is due to a wrong basic calculation of the power in the wprobe component, as in practice it computes the complex power as S = V I and flips the sign of the reactive power instead of using S = V I^*. So when using the probe to compute the power provided by a source, so measuring the voltage across the source, the current calculation works, as the voltage from the source is purely real. But when measuring across a component, as shown above, the voltage has a phase different from zero and the results are wrong.

After correcting the formula used the results are fine:

I'll open a PR with the fix soon...