One of our Admins are stuck in Godmode I deleted the whole Plugin but he is still in godmode
How can work that?
And how to fix that?

Sounds like they used Rust's "god true" setting in their F1 console.

How to disable it?

They would have to use "god false" in their F1 console, else remove them as owner/moderator natively in Rust.

Thank you so much it worked I wasted so much time trying to fix that cause only he was in Godmode
And why the second owner is not working?
I wrote ownerid and his iD in console and after save also server.writecfg
But every restart I need to write it again cause I want to give him also Owner

Not sure with the ownerid thing, but sounds like something else overwrote that file.

How to find out what is overwriting the file?