As seen in Bug 1937460, an error in OpenStack or a temporary failure can currently prevent the installation even if it would succeed.
The pre-flight checks should only be allowed to prevent the installation when they successfully collect data.
(shiftstack) [stack@undercloud-0 ~]$ oc get clusterversion
NAME VERSION AVAILABLE PROGRESSING SINCE STATUS
version 4.8.0-0.nightly-2021-05-21-233425 True False 138m Cluster version is 4.8.0-0.nightly-2021-05-21-233425
WARNING Empty OpenStack cloud info and therefore will skip pre-flight validation.
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 4.8.2 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.