Most codesandbox template does not support decorator
SyntaxError
/ src / index.js: Support for the experimental syntax 'decorators-legacy' isn't currently enabled (9:3):
7 | 8 | class Main extends React.Component {
9 | @observable internalState = false; | ^ 10 | constructor(props) { 11 | super(props); 12 | this.internalState = false;
'decorators - legacy' is supported in typescript template. Not for javascript pageYOffset