so when players run through portal to go to a different world I want it to change their game mode from survival to creative and change it back to survival when they run back through please help

/mvm set mode survival - do this in survival world
/mvm set mode creative - do this in creative world

Commands stated by UnFailed should be what you need. If you still have issues, you can create a new issue or ask in our discord https://discord.gg/NZtfKky