Hi, yes you are probably right. I'm assuming its not been off in a while. I had this on my D4. Lots of release oil or wd40. If you have the key turning fully i seem to remember knocking the latch mechanism with a metal driver + hammer under the car. But take care not to damage it. I only hit it faily gently.
3litre SE. Monticello Red. Electric deployable tow bar.