Why this circuit has a DC current?
From what I see your analysis is correct but for some reason you have an offset in the inductor current (it goes from 0A to 20A, when it should oscillate between -10A and 10A, just like the cap). I would guess that is the issue, maybe some simulation setup. I don't know where it is coming from, but I was able to simulate the circuit in LTSpice and I get the results you are expecting.