[iOS] Characteristic Update weirdness

[sktron]

Concerning Characteristic.ValueUpdated, I encountered two things:

1. CharacteristicReadEventArgs.Characteristic instance unrelated to the event?
   In my handler for said event, the Characteristic instance passed in the eventargs apparently always is some other of the characteristics I discovered for a device, not the one that was updated.
   Why would that be?

2. (sender as ICharacteristic).Value == null
   This one is probably due to our custom BLE device, which is the server, having faults in the GATT profile. But maybe it's not or could be handled better*, so I'll mention it.
   While we have transferred data from a small characteristic (5 bytes payload) via notification from BLE server device to the iPhone, a 20-byte payload one does trigger the Updated event, but the Value property of the characteristic instance passed-in as sender is NULL, I guess this should never happen, somewhere something is broken? When successfully receiving the reply on the 5-byte one, that was on the instance passed as 'sender' - so I suppose that's the correct instance to grab in the ValueUpdated handler.

Do you have any idea under which circumstances this could happen, i.e. what could be wrong in a GATT profile that would make this happen (generate ValueUpdated event with NULL for Characteristic.Value )?

Alas, in Peryton-BLE sniffer, I don't see the message which could be the "broken notification", whereas I do see the one which is received correctly.

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*' e.g. if faulty messages are received, there could be an event or other mechanism that notifies the application code that a device is sending non-conformant messages