That spring is too tight or is the wrong spring. The leg closest to the plate is already starting to take a short cut. It’ll do this if there is too much tension on the spring or if it’s the wrong material (not spring steel) when you use the kick starter that leg behind will jam up.

If you back the plate off half a turn and the kick start lever is sloppy then you have the wrong kind of spring.

You’ve also put teeth marks on the kickstart shaft which might bind on the case when it’s fitted.

Find a steel tube which slides over the shaft, then fit the kickstart lever (obviously the shaft will need to be cut so it’s the correct length and butted up to the lever when fitted.