I am working with an iPhone accessory that relies on ANCS for the majority of the product's functionality. Apple's ANCS documentation states the following:
"Due to the nature of iOS, the ANCS is not guaranteed to always be present. As a result, the NC should look for and subscribe to the Service Changed characteristic of the GATT service in order to monitor for the potential publishing and unpublishing of the ANCS at any time."
In practice, we have almost never seen such a situation occur. Recently, however, one of our test phones seems to hardly ever have ANCS present. This introduces complications with the user's ability to use the product.
Is there any way to know why ANCS might never be showing up for a particular user? Is there something we can do to indicate to the phone that this service is required at a given time?