With the 3.1.0 updates for Vault Provider for Terraform, there is a potentially breaking change to the
vault_jwt_auth_backend resource regarding namespace settings.
After upgrading to 3.1.0, the Vault UI OIDC prompt may not appear which consequently prevents successful login for users tied to OIDC.
Double check the argument
namespace_in_state for the
vault_jwt_auth_backend Terraform resource in the Terraform code - it may be set to
true by default causing the issue - switch this value to
false. If it is not in the code, adding the argument and setting it to
false should resolve the issue and result in the prompt reappearing during sign-in.