Good day,
It doesn't sound like HA should have kicked in at all in your circumstance as long as there were no unplanned host outtages. Do you have VM Monitoring enabled in your cluster HA settings? You'll definitely want to check the logs for evidence as to why this is happening.
Ensure each of your hosts can ping their isolation address, usually the default gateway of the management network. If you have VM Monitoring enabled, ensure VMware Tools is running in the VMs that had the error. You can also disable HA on the cluster and wait for the AAM agent to be uninstalled from each host, then re-enable HA.
If you don't want to disable HA cluster-wide, you can also remove individual hosts from vCenter. This will also uninstall the AAM agent. Once it's removed, re-add it to vCenter and the HA-enabled cluster. This will then re-install the HA agent.
Without looking at the logs, it's difficult to say exactly what caused your problem. Feel free to attach your log files here for the community to peruse.
Cheers,
Mike Brown