I'm pretty new to electronics, and so I've been modelling my circuits in a Falstad's circuit simulator.
I noticed something which I did not expect, and am curious - is this effect real, or is this a bug in circuit simulator?
I've reduced my circuit to the smallest circuit that shows the problem - shown here
My understanding of this circuit is that the diode should block the current from flowing from the right (12v) side to the left side, so the circuit becomes a 5v power source, connected to a resistor - should be at 5v.
Note: I want to understand what's happening, more than I want a solution. I know I can put in a smaller resistor, to make the problem less.