tensorflow 2.5 build for linux cannot access s3 file system

[GuyPozner]

OS: ubuntu 18.04
Conda version: 4.8.2
Build: mkl_py37h3e8b3f4_0
Using pip to install tensorflow 2.5, I am able to run:

CHECKPOINTS_PATH = "s3://some-bucket/path/to/checkpoint"
file_list = tf.io.gfile.listdir(CHECKPOINTS_PATH)

But when install it with conda I get the following error:

Traceback (most recent call last):
  File "tests/ckpt.py", line 31, in <module>
    files = tf.io.gfile.listdir(CHECKPOINTS_PATH)
  File "/homes/guyp/.conda/envs/tf25_check/lib/python3.7/site-packages/tensorflow/python/lib/io/file_io.py", line 772, in list_directory_v2
    message="Could not find directory {}".format(path))
tensorflow.python.framework.errors_impl.NotFoundError: Could not find directory <CHECKPOINTS_PATH>

This is true for any interaction with s3 filesystem I have tried.
Can you please help? provide information?