Hi, I run a 2011 Mk 3.5 and the temperature gauge sits at 1/3 all the time. Warms up within a mile or so at normal operating temperature after 10 minutes. The 3 cars I tested before buying this car all had a similar reading.
I had the Aircon refreshed a couple of months ago and the car was left idling for 15 minutes and the gauge stayed at a 1/3 and you could hear the cooling fan cutting in and out as required.
Hope this helps. As long as its registering and staying below 1/2 I don’t there is a problem.
My last car a 2.5 Euphonic used to sit at 1/2 way and move towards the 3/4 when in traffic on hot days before the fan kicked in.
I would put it down to a characteristic of the vehicle.
Cheers
Keith