Everyone can go into creative mode using gm 1 even tho the game is set to survival

Setting up a new server yah I know but this is for us sensory sensitive people I shut off the weather so no lightening ect.

HOWEVER, people can put themselves in creative mode using gm 1 in the command line. I do not what this and cannot find where to shut this off.

Found out what it was. In the default.json there is a line that says "changegamemode": true.

Not why that was set to true but lesson learned.