I’m afraid I don’t have enough information to identify the cause of the problem you’re having. Have you tried using live update and recording a session in FMOD Studio’s profiler window? Profiler sessions record how often event instances and voices are created, stopped, and virtualized, and so are a useful tool for diagnosing this type of issue.
For example, you may find that the event is being triggered so often that it is stealing every instance of itself before it can begin; if so, you could solve the problem by using cooldown without instance limiting, or by changing the stealing behavior.
I should probably mention that max Instances and Cooldown don’t directly interact and are designed for different purposes, so using both in the same event may be overkill.
Cooldown determines the minimum amount of time that must pass after an event begins playing before an new instance of that event can begin playing. Thus, if an event’s cooldown is set to 100 ms, and it has been only 40 ms since an an instance of the event was last started, it is not possible to play a new instance of the event. Cooldown is primarily used to prevent “spamming” of notifications or incidental dialogue.
Max Instances defines the number of concurrently-playing instances at which creating a new event instance causes the stealing behavior to come into play. It is primarily intended for limiting resource use, though it may also sometimes be used to prevent “spamming” of notifications and dialog.
When an event has both a finite max instances value and a cooldown, and your game’s code attempts to create a new instance of the event, the cooldown value is checked first, and only if the cooldown duration has been exceeded is the max instances value checked.