Clamp multimeter RMS current measurement, AC versus DC confusion
This answer was given before the OP revealed he was using output rectification


It's possible that there is some form of rectification in your secondary circuit and that the two components of your current are actually 20.5 volts DC and 9.7 volts AC. If you do an RMS mathematical combination of the DC and AC currents you get 22.68 amps RMS.

$$RMS = \sqrt{DC^2 + AC^2}$$