For whatever the reason it would appear that the main power supply to the radio isn't being maintained when you turn off the ignition.

This could be caused simply by one of the multiplugs in the back of the radio having come loose or something more complicated like a wiring fault.

As a first step I'd be inclined to pull the radio out from the dashboard and remove and then re-insert each of the multiplugs in turn. Hopefully, this may solve the problem.

If it doesn't then you will need to carry out a further investigation as to why the supply to the radio isn't being maintained.

Edited by Galaxy on 16/02/2019 at 07:50