Boot Lid Wont close/lock
 

I have a A8 (D3) 2008 4.0L Diesel.

When I close the trunk lid it doesn't lock. The soft close motor does start and I cant lock it manually with the key.

If I press the trunk unlock on the keyfob I can here a dull short click from the trunk lid.

Any suggestions what this might be or how I can investigate further.

Many thanks