Citroen c5 x7 front suspension struggling to stay up

[diasure]

I hope someone can help....

If I go to the car the front suspension is dropped in the lowest position (but the rear suspension fine).
If I open the door, start the engine, the front suspension will rise to the normal level. But it will slowly drop again, then correct and rise up, slowly drop again, then correct and rise up.....and so on. Every 10 seconds or so the drop - rise - drop - rise.
I can drive the car but I am aware of the continual sinking/rising - e.g. at traffic lights I can see it happening.
If I remove the key, lock, then the car sinks back down.

The impression is of a leak, or a valve not closing when it should...but no error messages, took it to my local independent and he could find no diagnostics and is at a loss. Any ideas please?

[EDC5]

I doubt it is a leak as it wouldn’t be able to lift itself up too many times.

It sounds as like (as you say) a leaky front lowering valve in the valve block. I’m not sure how this can be rectified without replacing the whole hydraulic block.

[GiveMeABreak]

Or your front height corrector is faulty. If this is on the way out it could be sending intermittent data causing continual correction.