Devices within a Casambi network can have multiple different control commands applied to them simultaneously. The software has inbuilt logic to tell devices what commands they should be acting on in such situations. This is called "Control hierarchy".
The most common reason for a command to appear not to work "as expected" is that a higher priority command is also active. e.g. Presence sensors will not activate a scene if you have previously manually switched the same luminaires to a different scene and the manual control time out period is still active. Timers will not appear to activate at the set time if presence sensors in an area are also detecting movement and overriding the timer command.
Even the process of programming a scene in the Casambi app may have the effect of activating manual control. Thus if you first program a scene and assign it to activate from a presence sensor, when you try to trigger the scene from the sensor you may find nothing seems to happen. This is because the manual control is still active from when you created the scene. To test the functionality you can "Resume automation". This can be done in the Luminaires tab by pushing the @ symbol.
Timers only send commands at the specific ON and OFF times assigned. For example; If you are actually doing programming at 11:00 and you set a timer to switch a scene ON at 9:00 and OFF at 18:00, the timer scene will not activate until 9:00 the next day. To test if a timer works you need to ensure no other commands are affecting the luminaires in the timer scene and then refresh the timer. To do this you need to reset the network (More → Network Setup → Configure all luminaires → Reset Network). You can then go to the timer screen, push "Edit" and then refresh the timer by pushing the refresh symbol.
For more information about Control hierarchy see the following articles: