There seems to be a crash problem with the SDK when device is disconnected and then connected.
Debugger throws following exceptions before crashing.
Managed Debugging Assistant 'CallbackOnCollectedDelegate' : 'A callback was made on a garbage collected delegate of type 'JabraSDK!JabraSDK.RegisterBatteryStatusUpdateFunc::Invoke'. This may cause application crashes, corruption and data loss. When passing delegates to unmanaged code, they must be kept alive by the managed application until it is guaranteed that they will never be called.'
System.NullReferenceException: 'Object reference not set to an instance of an object.'
This can also be reproduced with the SDK's Demo application. Although it might take some effort to produce the crash.
Easiest is to use a Jabra Link Dongle (Jabra Link 370) with Bluetooth headset (Jabra Evolve 65) and turning the headset off/on multiple times with the headsets 'power' switch.