See in /Assets/Plugins/FMOD/RunstimeManager.cs that ‘OnApplicationPause’ is used to execute the suspend resume logic, mentioned in https://fmod.com/resources/documentation-api?version=2.1&page=platforms-html5.html#safari-and-chrome-browser-user-interaction-requirement-use-for-all-browsers
It has to come from a callstack that is triggered from a user interaction. It cannot typically be passively called without a click or tap involved.