A capacitor's current is the slope of its voltage. Ramp 4.0 V in 2.0 ms through 2.2 µF and you get a flat 4.4 mA that flips sign the instant the ramp turns round.
https://www.electronicsinfoline.com/components/capacitors/capacitor-component/

Your bench supply says 12.00 V. With 0.25 Ω of lead resistance your board gets 11.375 V at 2.5 A. The display is measuring the supply's terminals, not your circuit.
https://www.electronicsinfoline.com/fundamentals/test-measurement/bench-power-supply/

Yellow, violet, orange, gold: 47 kΩ ±5%, so anywhere from 44.65 to 49.35 kΩ. Our new resistor colour code calculator does 3 to 6 bands and works backwards from a value to the nearest standard part.
https://www.electronicsinfoline.com/calculators/resistor-color-code

A 10 F supercap at 2.7 V holds 36.45 J. Let it sag to half voltage and 27.34 J has already come out, 75% of it, because energy goes with voltage squared. A converter that runs down to a quarter voltage gets nearly all of it.
https://www.electronicsinfoline.com/components/capacitors/supercapacitors/