Hi,
I have the same problem on my Medion 2021 notebook, the center pin wiggled around and has now broken off. I can't find a repair guide for it and rather than risking further damage, will have to get someone out to fix it for me.
When I do get it fixed, I am going to have the adaptor brought out of the case (on a cable), so that if the adaptor fails again, I can replace it myself without having to open up the casing.