power electronics - Why is the capacitor in this circuit not becoming an open circuit?

In this circuit you can find an RC circuit and 4A DC current source.

I thought that if we use a DC voltage source instead of a DC current source, this circuit would become open circuit after a while. Because the voltage on the capacitor is equal to the voltage source.

I've applied it the same way and thought about the case as DC current source. I think the result should be the same open circuit result.

But it's wrong and I don't know the reason.

This is my circuit and ? symbol is my question. Why this spot's current is not zero? I mean open circuit. This is simulink result and you can find this capacitor's current is still 4A (yellow line)!

Can you tell me why the current source in the RC circuit is not open circuit?