Hi,
Measuring current 29.95 mA (calibrated DMM)
It seems you want to measure very accurately.
Then you need to know the DMM's measurement method...and the operation of your load (LED).
* in a LED brightness mainly depends on average current
* in a LED the power dissipation mainly depend on average current
(With an incandescent light bulb for example it's not average current, but RMS current)
Thus with a PWM without storage inductance the efficiency is worse than with DC and resistor...
(Brightness to power consumption). But it's only marginal here.
Often good DMMs use true RMS calculation, but for your case you should use average value.
With 80% duty cycle the RMS value is about 9% higher than the average value.
If your aim is just to control the brightness, then everything is fine. The 9% deviation won't harm.
I recommend to reduce switching frequency. No need for 66kHz. 1kHz will be fine. This reduces EMI.
Klaus