A Windows template has a password set for the Administrator account. When the machine gets deployed with static ip via Aria Automation a customization specification is implicitly created to set the static ip on the deployed machine.
The customization spec used doesn't have a password set for Administrator. As a result the machine is deployed without a password set for the Administrator.
Either cloud-init or a vCenter customization spec with the admin password explicitly set can be used to set the desired password.
cloud-init example:
remoteAccess:
authentication: usernamePassword
username: Administrator
password: Password1234@$
For more information on cloud-init see Blogpost