basicConstraints with CA set to TRUE does not set CA to True

Hello There, I followed the instructions here.

  1. generating intermediate - used these params key_type=ec key_bits=256 add_basic_constraints=true

  2. defining role - used these params key_type=ec key_bits=256 key_usage=CertSign

Requested certificate (step #4), inspected the certificate and found out that CA is not set:

X509v3 extensions:
X509v3 Key Usage: critical
Certificate Sign
X509v3 Extended Key Usage:
Server Authentication, Client Authentication
X509v3 Subject Key Identifier:
X509v3 Authority Key Identifier:
X509v3 Subject Alternative Name:

Despite passing add_basic_constraints=true, CA is not set. What am I missing here? Any help is much appreciated.