My NextJS server executes a function called “loadAllUserPools” during start up. Here’s what the [abbreviated] file with this function looks like:

let userPoolMap = new Map();


export async function loadAllUserPools() {
  console.log('loadAllUserPools function started');
  // Triggered when the app starts. It gets all user pools
  // from the DB.

  // TODO: get data from db. Mocking DB data:
  const dbUserPoolData = [
    {
      cognitoUserPoolId: 'user-pool-1111111',
      cognitoClientId: '11111111111',
      accessUrl: 'tenant1',
    },
    {
      cognitoUserPoolId: 'user-pool-2222222',
      cognitoClientId: '222222222222',
      accessUrl: 'tenant2',
    },
  ];


  cognitoUserPoolList = [];

  // Update the cognitoVerifier list and the subdomain map
  dbUserPoolData.map((item) => {
    cognitoUserPoolList.push({
      userPoolId: item.cognitoUserPoolId,
      clientId: item.cognitoClientId,
      tokenUse: 'access',
    });
    userPoolMap.set(item.accessUrl, {
      userPoolId: item.cognitoUserPoolId,
      clientId: item.cognitoClientId,
    });
  });
  console.log('map: ', userPoolMap);
}

export async function getCognitoUserPoolBySubdomain(subdomain: string) {
  console.log('map: ', userPoolMap);
  const data = userPoolMap.get(subdomain);
  console.log(data);
  return data;
}

When the “loadAllUserPools” function executes, it prints the Map to the console with the expected values, which tells me that the map values are being properly set:

loadAllUserPools function started
map:  Map(2) {
  'tenant1' => { userPoolId: 'user-pool-1111111', clientId: '11111111111' },
  'tenant2' => { userPoolId: 'user-pool-2222222', clientId: '222222222222' }
}

Later when a user tries to login, I invoke the “getCognitoUserPoolBySubdomain” function, which tries to get a value from the Map. However, the map returns “undefined” when trying to find “tenant1”. Furthermore, printing the Map to the console shows a Map length of zero:

getCognitoUserPoolBySubdomain function started
map:  Map(0) {}
undefined

Any ideas on why this is happening?