Freelander 2 2.2 2010 coolant problem

Freelander 2 2010 coolant problem.
Recently noticed coolant loss. Have replaced the header tank and cap. I have noticed coolant on the top engine mount which leads me to believe that the coolant system is being subjected to excessive pressure. If I take the pressure off the cooling system by unscrewing the cap, there is no steam from the exhaust when starting the car the following morning. If I forget to take the pressure off the coolant system, I drive away for the first couple of miles with clouds of steam behind me like Jimmy Bond in his DB5.
No mayonnaise in oil, coolant is also fine. Following reading some posts, I have bought a new egr cooler and was just about to start fitting it today. Having done a pressure test today, I suspect that I may have other issues. The coolant system slowly lost pressure from 21 psi to 10 psi over 20 minutes or so.
I suspect I have an egr cooler fault due to the steam in the morning. As regards the overpressuring of the coolant system, I hope that this may be a water pump issue and hopefully not a head gasket failure or cracked head / block.
Vehicle otherwise drives / pulls well without warning albeit the coolant warning message sometimes is displayed, and I top up the system.
Any help or advice would be gratefully received.
Julian

Not sure if you've taken it apart but this was similar to my coolant loss problem, it was all in the valley and the ground, replaced the thermostat housing and coolant pipes and that solved the leak. Now it's overheating though but I just ordered a new reservoir tank and hoping that evens out the pressure as mines pretty cracked with spider lines.

8 out of 10 cases when it loses coolant and nowhere to be seen it's the EGR cooler. Even more possible when an EGR blank is in place.