Root cause of this issue is not clear as the issue did not reproduce in-house at Broadcom. Probably RMDeviceInventoryDelegate object goes out of scope in customer's App. When forcing this going out of scope behavior is the only way this issue is reproduced.
Devices running with iOS Client DDNA SDK version below 8.3.4.
Reference for RMDeviceInventoryDelegate object has been changed from 'automatic' to 'weak' as SDK may crash when automatic delegate goes out of scope. The fix has been provided in version 8.3.3 of ca-ddna-iOS-sdk-8.3.3