I believe you are calculating path every single frame using player's motion vector regardless of W or S input. As a result when some solid object pushes the player away it breaks the system. Alternatively you can bind the calculations to W or S input. Path should only be calculated when W or S is pressed.
Viewing post in Stellar Siege jam comments
1. For the first Saturn fight, when Saturn throw the large asteroid towards player in high velocity. This one is inconsistent to reproduce.
2. When I defeated the Sun, I was pushed back to the first boss. Now it had a celestial machine around him. At that instance, when the celestial machine pushed me into the planet. My orbital path started glitching out. This one is consistent to reproduce.