According to recently forum talk on DJI forum, it seems some of DJI Spark mini drone (DJI/Amazon/B&H Photo/Adorama) mysteriously shutting down and falling from the sky in midflight. You can take a look at one of the videos of their drone losing connection while they were still flying:
DJI spokesperson said that they are going to look into this issue and made a statement:
DJI is aware of a small number of reports involving Spark drones that have lost power mid-flight. Flight safety and product reliability are top priorities. Our engineers are thoroughly reviewing each customer case and working to address this matter urgently.
DJI products are tested for thousands of hours, and the overwhelming number of customers enjoy using our products with minimal disruption.
We are looking to implement additional safeguards with a firmware update which will be issued soon. When prompted on the DJI GO 4 App, we recommend all customers to connect to the internet and update their aircraft’s firmware to ensure a safe flight when flying their Spark.
This means new firmware for DJI Spark is coming soon. Stay tuned.