In One Identity Cloud Access Manager deployment, there is a STS host and Proxy host. The proxy host acts as the reverse proxy to protected applications, as well as serving as the Login Page.
On the Proxy host, if you ever need to restart the service, a quick search for One Identity Cloud Access Manager Proxy does the job. Fairly easy to locate.
On the STS host, if you need to restart the service, you are not in luck. It took me a while initially. I just could not locate any service that starts with "One Identity ...".
To do so, search for "Redistributable Secure Token Server" instead.
Weird and inconsistent naming convention indeed!