Uncaught (in promise) TypeError: Cannot read property 'Zi' of undefined at handleSheetsAuth (sheets.oauth.js:58) - Google Sheets API

[CPMikeAmato]

Expected Behavior

We've had a Browser-based web application live and in production for about 8 months now and all the sudden without any code changes, new versions built/deployed, etc, our connection to Google Sheets seems to have broken.

Some context of the app: a table displaying many rows of various types of String data, nothing crazy here. We are using DataTables to display this data in a "pretty" way and have an "export to google sheet" button for users to export and edit this data locally, etc.

Error message we're seeing in the console:

Uncaught (in promise) TypeError: Cannot read property 'Zi' of undefined at handleSheetsAuth (sheets.oauth.js:58)

Below is the function inside sheets.oauth.js that is causing the error, line 58 is the line:
"if(!signInStatus || !gapi.auth2.getAuthInstance().currentUser.Ab.Zi.scope.toString().includes(SCOPES)) {"

`
async function handleSheetsAuth(headerData, bodyData, pageName) {
let signInStatus = await gapi.auth2.getAuthInstance().isSignedIn.get();
if(!signInStatus || !gapi.auth2.getAuthInstance().currentUser.Ab.Zi.scope.toString().includes(SCOPES)) {
let signedIn = await gapi.auth2.getAuthInstance().signIn();
}

let formattedDate = new Date().toLocaleString();
let spreadsheetBody = {
    "properties": {
        "title": "lorem ipsum - "+pageName+" Export - "+formattedDate
    }
};
let request = gapi.client.sheets.spreadsheets.create(spreadsheetBody);
request.then(function(response) {
    //console.log(response.result); // response.result.spreadsheetUrl // response.result.spreadsheetId
    let dataRequest = gapi.client.sheets.spreadsheets.values.batchUpdate({
        "spreadsheetId": response.result.spreadsheetId,
        "valueInputOption": "USER_ENTERED",
        "data": [{
            "range": "Sheet1!A1:AE1",
            "majorDimension": "ROWS",
            "values": [headerData]
        },
        {
            "range": "Sheet1!A2:AE20000",
            "majorDimension": "ROWS",
            "values": bodyData
        }]
    });
    dataRequest.then(function(dataResponse) {
        window.open(response.result.spreadsheetUrl, "_blank");
        return "success";
    }, function(dataReason) {
        return console.log('error: ' + dataReason.result.error.message);
    });
}, function(reason) {
    return console.log('error: ' + reason.result.error.message);
});

}
`

Thanks all,
Mike