Stealth is also allowed for normal players?
He can still remain invisible after the deregulation

"oxide.grant group admin vanish.use",
"oxide.grant group admin vanish.damage.buildings",
"oxide.grant group admin vanish.damage.animals",
"oxide.grant group admin vanish.damage.players",
"oxide.grant group admin vanish.abilities.invulnerable",
"oxide.grant group admin vanish.abilities.teleport",
"oxide.grant group admin vanish.abilities.hideweapons",

If you do not want vanish for normal players, you'd need to check the "default" group to see if permissions were accidentally granted to them.

oxide.show group default