When a player tried to join the creative dimension for the second time, it was automatically triggering the process to send it back to the regular dimension.
The command used to get the value of the disable_portals_use setting showed the wrong one.
Added an extra security layer to keep players in creative mode in the creative dimension when the force-gamemode rule of the server.properties file is set on true.
Clicking "Yes" from the uninstall command output didn't launch the uninstalling process.