What is ejection button? Do you pin the end of the s-pen when it is inside the phone? Yes, that is not tightly fixed and moves just a bit in it's position.
I haven't got this problem on any Note I've ever used. You may have a broken S Pen. Head on over to Samsung and see if you can get it replaced under warranty or good will, because the newer gen s pens have many more sensors, Bluetooth and a battery, so it won't be cheap like the old ones.
We acknowledge your query and apologize for the same. We request you to kindly visit the service center for a physical inspection of your device. You can locate your nearest service center with this given link: https://www.samsung.com/in/support/service-center/
