Env variables not persisting in parent shell - bash

Question

I have the following bash script that attempts to automate the assuming of an AWS role (I've obviously removed the various private settings):
#! /bin/bash
#
# Dependencies:
# brew install jq
#
# Execute:
# source aws-cli-assumerole.sh
unset AWS_SESSION_TOKEN
export AWS_ACCESS_KEY_ID=<user_access_key>
export AWS_SECRET_ACCESS_KEY=<user_secret_key>
temp_role=$(aws sts assume-role \
--role-arn "arn:aws:iam::<aws_account_number>:role/<role_name>" \
--role-session-name "<some_session_name>")
export AWS_ACCESS_KEY_ID=$(echo $temp_role | jq .Credentials.AccessKeyId)
export AWS_SECRET_ACCESS_KEY=$(echo $temp_role | jq .Credentials.SecretAccessKey)
export AWS_SESSION_TOKEN=$(echo $temp_role | jq .Credentials.SessionToken)
env | grep -i AWS_
I have to execute this script using source because otherwise if I use standard bash or sh the exported environment variables are not available within the parent shell executing this script.
The problem is, even when using source it doesn't work; and by that I mean: the environment variables AND their correct/updated values are showing in the parent shell (if I execute env | grep AWS_ I can see the correct values).
If I then try to use the AWS CLI tools (e.g. aws s3 ls - to list all s3 buckets within the specific account I've assumed the role for) it'll report back that the access key is invalid.
BUT, if I manually copy and paste the environment variable values and re-export them in the parent shell (effectively overwriting them with the exact same values that are already set), then the AWS CLI command will work - but I do not know why. What's different?

Answer 1

jq .Blah will return the output quoted.
So for example
export AWS_ACCESS_KEY_ID=$(echo $temp_role | jq .Credentials.AccessKeyId)
Will result "KEY" instead what you need is just KEY which is why your xargs works in your comment.
If you use the -r flag for raw with jq you will get the result you want
export AWS_ACCESS_KEY_ID=$(echo $temp_role | jq -r .Credentials.AccessKeyId)

Answer 2

Another way to assume an AWS role:
Write a profile, which automatically assumes the role.
aws configure --profile new-profile set arn:aws:iam::<aws_account_number>:role/<role_name>
To give credentials to the new profile, you must use one of the following lines:
aws configure --profile new-profile set source_profile default
aws configure --profile new-profile set credential_sourceEc2InstanceMetadata
aws configure --profile new-profile set credential_source EcsContainer
Line 1 was correct on my personal pc, because I used the default profile.
Line 3 was correct when I tested the code with AWS CodeBuild. The new profile used the credentials of the codepipeline-role.
Afterwards, you may use the new profile, example:
aws --profile new-profile s3 ls s3://bucket-in-target-account
Documentation: https://docs.aws.amazon.com/cli/latest/topic/config-vars.html#using-aws-iam-roles