I have an add-on which utilizes the addOns.common.homepageTrigger function to show a sidebar (https://developers.google.com/apps-script/add-ons/concepts/homepages)

If the user clicks the add-on button in the quick access panel it works just fine, however if they close the sidebar and then click the button in the quick access panel again, a placeholder page appears but nothing else happens:

{
  "timeZone": "Australia/Sydney",
  "exceptionLogging": "STACKDRIVER",
  "runtimeVersion": "V8",
  "dependencies": {
    "enabledAdvancedServices": [
      {
        "userSymbol": "Drive",
        "serviceId": "drive",
        "version": "v2"
      }
    ]
  },
  "oauthScopes": [
    "https://www.googleapis.com/auth/script.scriptapp",
    "https://www.googleapis.com/auth/documents.currentonly",
    "https://www.googleapis.com/auth/spreadsheets",
    "https://www.googleapis.com/auth/presentations",
    "https://www.googleapis.com/auth/script.container.ui",
    "https://www.googleapis.com/auth/drive",
    "https://www.googleapis.com/auth/drive.apps.readonly",
    "https://www.googleapis.com/auth/script.external_request",
    "https://www.googleapis.com/auth/script.locale",
    "https://www.googleapis.com/auth/userinfo.email"
  ],
  "urlFetchWhitelist": [
    "https://cm234-wgs-1.icognition.cloud/",
    "https://docs.google.com/feeds/download/documents/export/Export",
    "https://docs.google.com/spreadsheets/export",
    "https://docs.google.com/feeds/download/presentations/Export"
  ],
  "addOns": {
    "common": {
      "name": "Ingress Records",
      "logoUrl": "https://hydrakubernetes.icognition.cloud/images/ingress_icon_black_40.png",
      "homepageTrigger": {
        "runFunction": "showSidebar",
        "enabled": true
      }
    },
    "sheets": {},
    "docs": {},
    "slides": {}
  }
}

function showSidebar() {
  var sidebarName = "sidebar";

  if (getRecordUri() !== 0) {
    sidebarName = "existing_record_sidebar";
  }

  var ui =
    HtmlService.createHtmlOutputFromFile(sidebarName).setTitle(
      "Ingress Records",
    );

  getUi().showSidebar(ui);
}