After codify S3 cloudformaiton, see this: Recoverable error occurred (Inaccessible host: `cloudformation.us-east-1.amazonaws.com....'

NOTE: I manually created s3 bucket before, during which time I did not see the following warning message; but I feel I want to codify the whole stack into my project so I added the S3 cloudformation script into the project. And then this warning happened.

I have a serverless project that contains the following stack

/src/serverless.yml
    /handler.js
    /aws_cloudformations/s3.yml
                        /dynamodb.yml

After I added s3 into the script, I found that I run into the following warning message (the sls deploy succeeded after 4 attempts, which does not affect me too much). But I would like to know why this happened.

#sls deploy



Serverless: Checking Stack update progress…

........................................................................................................................................................................................................................................................................Serverless: Recoverable error occurred (Inaccessible host: `cloudformation.us-east-1.amazonaws.com'. This service may not be available in the `us-east-1' region.), sleeping for ~5 seconds. Try 1 of 4

Serverless: Recoverable error occurred (Inaccessible host: `cloudformation.us-east-1.amazonaws.com'. This service may not be available in the `us-east-1' region.), sleeping for ~5 seconds. Try 2 of 4

Serverless: Recoverable error occurred (Inaccessible host: `cloudformation.us-east-1.amazonaws.com'. This service may not be available in the `us-east-1' region.), sleeping for ~5 seconds. Try 3 of 4