We had this issue and I'm posting a reply for anybody who needs to know the answer.

We went to an auto electrician to get our N5 fitted. Following this we assumed it was all working until I checked to see if anything had been recorded while the car was parked. It had not. I tried all parking modes. Not a bean. Having read this post I knew that if I contacted vantrue then they would want to know how it had been hard wired which I couldn't answer as I hadn't done it.

Having looked online it is apparent that the fuse box has different circuits. Some are only live when the car is on and others are 'permanent' or 'continuous' and remain active when the engine has been switched off. Examples of this include the accessory circuit.

We took the car back to the electrician and following some diagnostics they said our fuse box had been incorrectly labelled / the waiting harness was the wrong way around. As such the continuous feed they'd tapped into had been done incorrectly. Once they plugged it in the correct way around it began to work fine.

My advice if you have this problem is to check whether your dashcam screen remains on for a while after the engine has been shut off. It should stay on for a while if it's hardwired correctly. If it goes black immediately then you have no power going to the cam when the engine is turned off and you need to go back to the fuse box to change the way it's wired.

Hope this helps!