Secondary On-Call is not displaying on calendar as expected.
Configuration of schedule entry
The behavior seen is due to the schedule the times listed in the schedule entry.
Notice the schedule entry for user is set for 17:00 starting on 7/16. However, it appears you are expecting him to also be part of the On-Call group from 00:00 - 09:00 on 7/16. In this case the start time on the schedule entry will need to be changed from 17:00 to 00:00.