Jerky Camera Movement

Good afternoon, everyone. What is wrong with this camera movement?


In first case, we are manually moving the camera behind the Snowball, but the camera movement is a bit jerky.

But if you just attach the camera to the Snowball instead, everything works smoothly. The problem is that I need the first case with manual movement.

If anyone has any ideas on how to solve this, please help me

P.S: I filmed a video showing it:
00:00 - Normal, Smooth Camera Movement (With parenting)
00:25 - Jerky Camera Movement (With this code, first case)