I watched the video
But I am in a place with noise and can’t hear the sound

However one detail concerns me
Whoever is stepping on the stomp starter in that video isn’t doing the truck any favors

You must do just what the name implies
Stomp! On it
Push it to the floor like you mean it!
Do not gently press it down
That’s not how it’s suppose to work
Stomp! Hard every time

I think you might have dirty worn contacts under that starter switch or dirty brushes
But I didn’t hear it
-s