Hi @amateur-dev,
It sounds like you have OpenZeppelin CLI installed globally and locally in your project.
oz --version will show the version installed globally and any oz commands will use the global version.
npx oz --version will show the version installed locally in your project and any npx oz commands will use the local version.
To see what packages you have installed globally you can ask npm to list the global packages (depth 0):
npm ls -g --depth=0
To uninstall the global version, run npm uninstall -g @openzeppelin/cli
To install OpenZeppelin CLI globally, run npm install -g @openzeppelin/cli
I tend to only have ganache-cli installed globally and depending what I am working on OpenZeppelin CLI (see: Installing packages locally rather than globally (npx))