TPU in experiencing issues with running code on Google Colab, particularly when using the TPU

Question

I have a problem when using the resolver code in Google Colab, it continues to run without any result either an error or the TPU result. I tried working from more than one account and also devices, and I have the same problem.

import tensorflow as tf
import os

# Note that the `tpu` argument is for Colab-only
resolver = tf.distribute.cluster_resolver.TPUClusterResolver(tpu='grpc://' + os.environ['COLAB_TPU_ADDR'])

tf.config.experimental_connect_to_cluster(resolver)
tf.tpu.experimental.initialize_tpu_system(resolver)
print("All devices: ", tf.config.list_logical_devices('TPU'))

strategy = tf.distribute.TPUStrategy(resolver) 

and I updated the TensorFlow but dose not work

I check this by going to Runtime -> Change runtime type and selecting TPU as the hardware accelerator.