When generating a Session Report after the loadtest I will only get values (min/max/avg) when using “show End-to-End Times (including Think Times)” and no values if using “Show server times only”.
Server Response times are generated only for http calls. If you notice 'Response Time' column in OpenScript it will be blank for your step group but 'Duration' will be reported. 'Duration' in OpenScript becomes 'End-to-End response time' in OLT and 'Response time' column in OpenScript becomes 'Server Response time'/
Not sure what 'callTokenServer' does. If it makes a http call, then consider using OpenScript http API to overcome this problem.