Why is the voltage drop across R2 0V despite 331nA flowing through it?

Wrong resistance. MegaOhm is meg, not m.

@Richie Fan Because

1.4M

in spice means 1.4 milli-Ohm, so to 5 digit precision there is no observable voltage difference (460pV). If you meant 1.4 Mega Ohm use

1.4MEG

Oh wow, that’s why it never worked whenever resistor value went above 1 meg, thank you