Externally mounted S3 bucket shows unexpected behavior

We have mounted an S3 bucket using the external_storages app on our NextCloud installation. But we are facing the following issues with it

  1. The file size is always pending
  2. The last modified shows random values. So on what basis is this value decided?
  3. When we go too deep down the file hierarchy in the mounted S3 bucket, it takes a lot of time to load the contents of the bucket

Can you help us out with how we can resolve these issues or what is the root cause of them?