Opensearch Serverless 'search_phase_execution_exception' Error when querying index

I'm trying to do a search query to my Opensearch Serverless index but i keep getting the following error:

 403 - Forbidden: {
  "code": 403,
  "message": "search_phase_execution_exception: [security_exception] Reason: Bad Authorization"
}

Here is my function to query the index:

const searchDocument = async ({ index, document }) => {
    const query = { query: { match: { description: document } } };
    console.log('query search document:', query);
    const checkingSearch = await client.search({ index, body: query });
    console.log('checkingSearch:', checkingSearch);
    return checkingSearch;
};

I thought it may have been an IAM permission issue, but I'm using the same permissions I have for a separate lambda function where it is updating the index and it works fine. Here is a snippet of my IAM permission:

iamRoleStatements:
            - Effect: Allow
              Action:
                  - aoss:APIAccessAll
                  - aoss:DeleteCollection
                  - aoss:UpdateCollection
              Resource:
                  - arn:aws:aoss:${aws:region}:${aws:accountId}:collection/open_search_collection_id
            - Effect: Allow
              Action:
                  - aoss:DashboardsAccessAll
              Resource:
                  - arn:aws:aoss:${aws:region}:${aws:accountId}:dashboards/default
            - Effect: Allow
              Action:
                  - aoss:*
              Resource:
                  - '*'
            - Effect: Allow
              Action:
                  - dynamodb:GetItem
                  - dynamodb:Query
                  - dynamodb:BatchGetItem
              Resource: 'arn:aws:dynamodb:${opt:region, self:provider.region}:*:table/${opt:stage, self:provider.stage}-DBNAME*'