Hello @PopularDust275.
Ghost mode, or invisible mode, was included in these versions of the trainer:
But removed in later versions. You can see these previous versions of the trainer by clicking the History button, which is underneath the Play button. Though there’s no guarantee an older trainer will work with the latest game version.
I do not have any information on why this specific cheat was removed. However, when a cheat is removed it is usually because it either caused issues with the game or the cheat was made too difficult or even impossible to create due to particular updates to the game.