After many instances of battery drain issues on MY 2019 and newer of Land Rover vehicles, JLR Canada has issued an update (SSM 74634) which is intended to solve this issue of the vehicle controllers staying awake for a prolonged period of time after the vehicle is turned off.
Issue: Battery drain when dongle or any device is installed on the OBD port (except JLR diag tool)
Discovery / L462
Discovery Sport / L550
New Range Rover Evoque / L551
Range Rover Velar / L560
JLR Canada has recently released SSM 74634 for the battery drain issue when dongle is connected in relation to the OBD devices.
A simple update of the vehicle will allow you to connect you OBD dongle to the vehicle without any issues. If issues do persist, please let our engineering know at firstname.lastname@example.org and also inform JLR Canada of the matter.