AWS Cognito issues codes which are invalid grants when using AWS SDK 3.263.15 and AWS CRT 1.2.4

[tim-hitchins-ekkosense]

Describe the bug

When I have AWS SDK 3.263.15 and AWS CRT 1.2.4 installed, the login code returned by Cognito is not valid - a curl to https://user-pool-name.auth.eu-west-1.amazoncognito.com/oauth2/token with that code gives {"error":"invalid_grant"}.

Expected Behavior

The code returned should be valid and a request to /oauth2/token with the code should give a valid token.

Current Behavior

The code returned is not valid and a request to /oauth2/token gives {"error":"invalid_grant"}

Reproduction Steps

Attempting to assemble one

Possible Solution

No response

Additional Information/Context

This does not happen in version 1.2.3 with the same AWS SDK

aws-crt-php version used

1.2.4

php version used

8.1.18 Zend Engine v4.1.18

Operating System and version

Ubuntu 22.04.3 LTS in WSL