Installable trigger is just keep getting disabled

I have been trying to install an installable trigger for a googlesheet workspace addon when a button is clicked. The trigger is meant to get fired whenever a cell is modified.

Unfortunately when a cell is modified, the trigger keeps getting disabled. The "disabled reason" (in Apps Script > Triggers > Last run column in the list) says: This trigger has been disabled for an unknown reason. I have tried calling from onHomepage() also.

Here is the code:

function createWidgetDemoCard() {
  return CardService
              .setHeader('Simple widgets')  // optional
              .addWidget(CardService.newTextParagraph().setText('Some text'))
                                                  .setText('Create trigger')

function createSpreadsheetOpenTrigger() {
  var ss = SpreadsheetApp.getActive();
      .onEdit()    //onChange() not working`enter code here`

function TestMe(e) {
  var range = e.range;
  range.setNote('Last modified: ' + new Date());

The authscopes are:

"oauthScopes": [

The code from the TestMe() function works perfectly in a container-bound script. But because I am developing a Workspace addon, I want in a standalone script.

I can't really find a comprehensive documentation about developing an workspace addon. Thanks!