Cannot connect to AWS RDS MySql using IAM from EC2 instance - mysql

Question

Using these commands
bash $ RDSHOST="xxxxxxx.mydbid.us-xxst-x.rds.amazonaws.com"
bash $ TOKEN="$(aws rds generate-db-auth-token --hostname $RDSHOST --port 3306 --region us-xxst-x --username some_name )"
bash $ mysql --host=$RDSHOST --port=3306 --ssl-ca=rds-ca-2019-root.pem --user=some_name --password=$TOKEN
I get this error
ERROR 1045 (28000): Access denied for user 'some_name'#'123.123.123.123' (using password: YES)
When logged into the database and running
SELECT USER, PLUGIN, HOST FROM mysql.user WHERE USER LIKE'%some_name%';
I get this:
+-----------+-------------------------+------+
| user | plugin | host |
+-----------+-------------------------+------+
| some_name | AWSAuthenticationPlugin | % |
+-----------+-------------------------+------+
1 row in set (0.02 sec)
This is the policy applied to the role
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"rds-db:connect"
],
"Resource": [
"arn:aws:rds-db:us-xxxx-x:123123123123:dbuser:db-QPASDASDASDASDASDASDASDASD/admin_user",
"arn:aws:rds-db:us-xxxx-x:123123123123:dbuser:db-QPASDASDASDASDASDASDASDASD/some_body",
"arn:aws:rds-db:us-xxxx-x:123123123123:dbuser:db-QPASDASDASDASDASDASDASDASD/some_name"
]
}
}
Also, IAM is enabled on the RDS database. The certificate .pem file is in the same folder as where I'm running the commands.
I've been over this guide, and this guide, and this guide.