Have you removed the plastic reservoir to see what is happening underneath?
The Coolant Level Sensor underneath is situated underneath and has a thin small black rubber grommet keeping it in place. This small grommet had a tiny tear on my 2002 Export 2.5 CRD which caused a very slow leak. Could not get another grommet so glued the sensor back with a good silicone compound.
The smaller pipes coming off the plastic reservoir could also be chaffing to chassis/engine somewhere.
Two day ago I suddenly got a Low Coolant message and the coolant was indeed low. Upon compressing the top radiator hose I saw a spurt of water from the 15 mm black hose coming from the coolant tank to the oil cooler. The hose had been chaffing on the engine just above the alternator pulley. I was able to cut off the last 9 inches of hose and with some minor re-routing of this hose I was able to attach it back in place neatly.
I opened up the flat black plastic plug on the top of the radiator and filled up with clean water until it flowed out and refitted the plug. I now need to by some Mopar HOAT anti-freeze to get the water-HOAT ratio better.......here in SA I have to pay the price for Mopar supplies as we do not have access to all the good alternative parts suppliers as USA owners have!