But the camera is jerky while performing the second transition, i.e., from the side camera to main camera and while in side position the camera rotates awkwardly with mouse, i.e., along the x-axis.
I attempted to repair the setup you are using but I ran into the same issues. Here is the solution that I came up with. It smoothly moves and rotates the camera to the location and back again.
Yeah you can disable just the mouse movement by using a ‘Set Ignore Look Input’ node instead of the disable/enable node. The idea for the setup I created above was so a mini cinematic or kill animation could play.