Can that be possible explanation?
but when current goes in a direction of the capacitor and R2, than it splits and some of current goes through R2 into the ground on the original voltage source.
Path is closed, since one part of current flows into the earth terminal.
When you close the switch, eventually the time-dependent behavior of the components ends ("step response".) The capacitor acts like an open circuit, the inductor acts like a short, and you're left with a simple voltage divider consisting of R1, R2, and the power source. So the initial voltage on the cap, and current in the inductor, are going to be dependent on the ratio of the resistors. And thus the amplitude to the oscillations when you move the switch as well.If you close the switch for less time than it takes to reach a steady state, the resistors will still be acting as a voltage divider...