Coolant loss 2015 focus ecoboost

[Prazer49]

Hi, seem to be loosing coolant from this focus, its a 2015 1.0 ecoboost. Had it up on ramps and cant see anything obvious, strange part is that although the coolant is dissapearing if i leave it parked up for two days the system is still pressurised when i remove the cap?

Put a pressure test on it, pumped up to 25 psi and it dropped about 4psi over an hour then stabalised

May be related or not, but earlier this week when accelerating hard for half a mile it came up with a reduced power to lower engine temp message, 30 seconds later it had cooled and back to normal?

Any ideas please??