Blue Box Chiller = Stumped! (UK Slang for confused)

[Grizzly]

Hi Guys.
I was wondering if anyone can unravel the gem I came across today?
Went to site to do a Straight forward "Look and Log" on 3 Blue Box Beta SLN 2002 Air cooled Water Chillers.
With their version of the pCO2 controllers, each chiller has 2 large scrolls Danfoss / Maneurope style. To each, of their 2 circuits.
2 coolers are fine, whereas on the last cooler 1 circuit is randomly locked out on "High Press Frigo Circuit 2"?

Ok HP Fault, straight forward enough! Wrong
Discharge pressure readout (Via a Druck pressure transducer) rises and falls as expected.
Discharge Pressure switch (1 per Comp) wired in series, so a common fault and have reset buttons.
Basically I disconnected the wiring for the 2 HP related Inputs on the Controller.
I did a “3pin reboot!”, checked for loose terminals etc.
Continually pressing the Alarm reset to see the alarm clear then reappear!
Even though the discharge pressures were well below their trip and differential settings.
Finally the alarm reset itself.
Circuit 2 ran and tripped before I could monitor the fans running and the displayed HP pressure.
Try again, this time the plant ran with discharge rising and the fans modulating with system pressure rise and fall. All Good!
Chiller goes off at setpoint. 5 minutes later with chiller at standstill (Stat satisfied!) the chiller goes into alarm. Displaying “High Press Frigo Circuit 2”?
Any ideas?
Thanks Grizzly
Just to add I have maintenance and service access codes so I cross checked settings I can access and they are the same as the other two chillers.
Whether a setting is corrupted at factory level I cannot say.