FOSS gamedev and creative worlds

I try to set up a dedicated server, but if I login I have creative mode. It worked the first time, then I stopped the server, start again and since then I have creative mode

world.mt

You're the god of the world. You have all privileges - creative aswell.
If "/revoke <yourself> creative" does not work, set the variable "name" in the server's minetest.conf to another nickname that can not be used by new players.

I had no creative priv before and if I log in as new user I also get creative priv

I can try to log in from another PC to see if I still have creative priv

Do you type /set -n creative_mode false and /set -n enable_damage true in game? If so it will reset on every server restart.

No, not me. But maybe a player? I did not change any privs and I don't know which privs player have

It just happens if I start the server from the terminal. If I start the GUI everything is OK. I tinker around a bit and now it works again. No idea what makes the change