The Server Object is missing permissions to be able to call Server_RequestServerStateChange. It worked for us since we have namespace default permissions for OPC UA namepsace with call permissions for Authenticates user. But it depends on the namespace default if it works or not.

Therefore we need to add the following setting for Server:
Server,2253,Object,,"{'Anonymous':'(1) Browse','ConfigureAdmin':'(65423) All','SecurityAdmin':'(65423) All'}"

To be able to call:
Server_RequestServerStateChange,12886,Method,"[SigningRequired]","{'ConfigureAdmin':'(61455) All','SecurityAdmin':'(61455) All'}"

Similar to:
ServerConfiguration,12637,Object,,"{'Anonymous':'(1) Browse','ConfigureAdmin':'(65423) All','SecurityAdmin':'(65423) All'}"