According to DJI latest release on their website, the latest firmware versions for the T40 and remote is shown on picture below.Ā Maybe the one you have is still demo and hasn't been released yet. I would suggest you to downgrade to the one shown on the picture below.Ā Ā
Sorry for the issue you have with your T40.
This error should be resolved with updating the firmware of the drone and the battery.
Sincerely,
Technical support
RUJ DRONESĀ