The NSX upgrade was stuck in precheck, and it was showing the wrong targeted version for upgrade, and also, the source version was wrong.
Wrong source version and/or target version can be seen in UC log on the NSX manager (/var/log/upgrade-coordinator/upgrade-coordinator.log)
INFO localhost-startStop-1 UpgradePlanServiceImpl 47977 SYSTEM [nsx@6876 comp="nsx-manager" level="INFO" subcomp="upgrade-coordinator"] Persisting Plan {"upgrade_status":"PAUSED","source_version":"####","target_version":"####"
VMware NSX
The target version update was skipped because the driving NSX manager node was different. This has resulted in a problem with the host upgrade progress.
Currently, there is no resolution. Please contact Broadcom Support to apply the workaround