991.2 coolant issue

[Hian]

Hi,
last week, after stopping for petrol part way through a journey, upon engine restart I get a high engine temp error with the instruction to turn off the engine and allow the car to cool. The coolant temp is way above an indicated 120C where it s normally rock steady at 90C, so I stop for 10 mins, restart and the temp is at 90C until I pull away and then rockets to >120C with fans kicking in at full rotation. I pull over once more and 10 mins later restart and all is OK and had no issues since. However have had the car in the dealers since Thursday and seems like they're saying there's some issue whereby the coolant level doesn't settle unless the car is put into sport mode - I've not had any issues in almost 2 years and 13K mls of ownership. Anyone else had anything similar?
Waiting for an update Monday as to what the issue maybe, but hoping there's been no secondary issues of this possible overheating.

[Pope]

Some 991.2 had reservoir/sensor problems and the part was replaced under a campaign; check if yours was affected - though the OPC would know this immediately.

The thermal management system on 991 can bring a complex diagnosis though......

[Hian]

Pope said:

Some 991.2 had reservoir/sensor problems and the part was replaced under a campaign; check if yours was affected - though the OPC would know this immediately.

The thermal management system on 991 can bring a complex diagnosis though......

Had the reservoir replaced so shouldn't be that. Thanks.