Trying to upgrade ESX hosts from 9.0.2 to 9.1 fails with "Device compatibility must be verified manually" and "No compliant devices were found." This will be present on VSAN hosts in the cluster.
The firmware section of cluster image compliance scan shows an empty value for the Firmware Version:
Cisco Intersight HSM is not certified or supported for vLCM HCL validation. This lack of certification is the reason the hardware compatibility check fails to retrieve firmware data, resulting in a blank firmware status.
Stop using HCL validation for firmware in vSphere Lifecycle Manager (vLCM) until a version of Cisco Intersight HSM is released that officially supports this feature.
vLCM Remediation Warning: Firmware Information Unavailable Without Hardware Support Manager
https://knowledge.broadcom.com/external/article?articleNumber=412988
VMware Hardware Compatibility Matrix
https://compatibilityguide.broadcom.com/
Contact Broadcom support for additional assistance