Troubleshooting a Programmer Instrument

I am having trouble getting my programmer instruments to play any sound. Debugging into the code shows me all RESULT.OK all the way through

  parameter.sound = dialogueSound.handle;
  parameter.subsoundIndex = dialogueSoundInfo.subsoundindex;
  Marshal.StructureToPtr(parameter, parameterPtr, false);

from the example C# script. I added a Programmer Instrument to an Event, the event is part of all my localized banks. The variable values in the code also show that the bank has been found and the pointer is pointing to something other than 0 at least.
The sound files are in my streaming assets folder, the bank has been rebuilt and I can listen to the sounds in fmod studio. I used audio files of different lengths and the DESTROY_PROGRAMMER_SOUND event is fired accordingly - so it seems that the files are found.

Yet, no sound is playing at runtime. Other FMOD events are playing just fine.
Is there anything else I can do here to debug this?


Using a 2D Timeline instead made me hear the sound.

Was missing