Can not apply client authentication to MSK cluster with both TLS and IAM

Hello,
I want to create MSK in AWS using terraform v. 1.0.11
I am using aws provider with latest version 3.73
and creating Resource: aws_msk_cluster
the cluster creation finished successfully
but when I am trying to apply client authentication with both tls and I am
with the code:
client_authentication {
tls {
certificate_authority_arns = var.certificate_authority_arns
}
sasl {
iam = true
}
}
I am getting the error:
“client_authentication.0.sasl”: conflicts with client_authentication.0.tls

choosing one of the method works
from the UI I can enabled them both

Need your advise ,what am I missing ?
Thanks
Riki