Changing NTP from SDDC manager errors hosts are in Maintenance Mode

Recently, I experienced an issue while updating the NTP server from the SDDC manager in the VCF 4.4 environment I got the below error:

Below is the log snippet from the operations.log file:

2022-12-20T10:00:58.112+0000 ERROR [vcf_om,8d4d9d24a43c4cc6,c749] [c.v.v.s.a.ValidateEntitiesInSystemAction,pool-2-thread-9] Validation errors [EntityValidationResponse(name=esx02.corp.local, ipAddress=192.168.10.12, fqdn=esx02.corp.local, type=HOST, errorCode=SYSTEM_CONFIGURATOR_HOST_IN_MAINTENANCE_MODE, entityValidationStatus=ENTITY_VALIDATION_FAILED, entityValidationErrorMessages=[Host esx02.corp.local is in MAINTENANCE mode.],

2022-12-20T10:00:58.113+0000 ERROR [vcf_om,8d4d9d24a43c4cc6,c749] [c.v.e.s.o.model.error.ErrorFactory,pool-2-thread-9] [1ID413] ENTITY_VALIDATION_FAILED Error occurred while validating details of entities.
com.vmware.evo.sddc.orchestrator.exceptions.OrchTaskException: Error occurred while validating details of entities.
        at com.vmware.vcf.systemconfigurator.action.ValidateEntitiesInSystemAction.execute(ValidateEntitiesInSystemAction.java:111)
        at com.vmware.vcf.systemconfigurator.action.ValidateEntitiesInSystemAction.execute(ValidateEntitiesInSystemAction.java:31)
        at com.vmware.evo.sddc.orchestrator.platform.action.FsmActionState.invoke(FsmActionState.java:62)
        at com.vmware.evo.sddc.orchestrator.platform.action.FsmActionPlugin.invoke(FsmActionPlugin.java:159)
        at com.vmware.evo.sddc.orchestrator.platform.action.FsmActionPlugin.invoke(FsmActionPlugin.java:144)
        at com.vmware.evo.sddc.orchestrator.core.ProcessingTaskSubscriber.invokeMethod(ProcessingTaskSubscriber.java:400)
        at com.vmware.evo.sddc.orchestrator.core.ProcessingTaskSubscriber.processTask(ProcessingTaskSubscriber.java:520)
        at com.vmware.evo.sddc.orchestrator.core.ProcessingTaskSubscriber.accept(ProcessingTaskSubscriber.java:124)
        at sun.reflect.GeneratedMethodAccessor1345.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:87)
        at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:72)
        at org.springframework.cloud.sleuth.instrument.async.TraceRunnable.run(TraceRunnable.java:67)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)

Though all the ESXi hosts are not in Maintenance Mode confirmed by the vSphere client:

Post-further research found that this is caused by the mismatch in FQDN - upper vs lower case.

The workaround that I followed here is to modify the FQDN on the hosts to be lowercase.

Post this I re-started the failed task from SDDC to update the NTP and this time the update of the NTP details task succeeded.