ESXi host root account getting locked will not impact host connectivity from vCenter Server. For more information, you may read VMware Knowledge Base
Host being disconnected from the vCenter refers to a different problem, you need to review the host log to identify the root cause.
Let us know if you need additional information 'or' have any other questions that I can help with.
Well our host went disconnected when a vulnerability scan was run on it as well as the root account being locked and never did unlock. It would not reconnect when we tried, we finally had to move all the guest off and reboot the esxi server and it reconnected. vmware support suggested it was the backup but none were running at the time only the vulnerability scan
These instances may appear during VM back up or exceeded number of open SOAP connections to the host occurs due if you have multiple VMware Infrastructure Clients connected to the same ESXi (for example, to access some VMs' consoles), reviewing the logs intensively will help us to identify the cause you may ask Support Team to review the logs once again with the assistance of senior SME and encourage you to ensure that ESXi host is timely updated with latest patches and running on latest builds.