There are several bugs blocked by the requirement to upgrade Terraform. In order to accomplish this, each of OpenShift platform needs to be converted to steps. This BZ is to cover IBM Cloud's conversion.
[QA Summary] Despite IPI IBMCloud is still under development and we can't achieve a complete installation yet, bypassing BZ#1992777 with "openshift/installer/pull/5147", I've widely tested the changes from the corresponding PR (openshift/installer/pull/5116), the installation successfully creates the control-plane VMs, cos bucket instance, LBs, DNS records, security groups, etc, it even successfully completes the bootstrap process. Therefore, I'm proceeding to mark this BZ as VERIFIED.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: OpenShift Container Platform 4.9.0 bug fix and security update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2021:3759