To be honest, it sounds like the thermostat is stuck open. As the engine cools, the thermostat should begin closing to restrict coolant flow. That is what keeps it at operating temp. If it is stuck open, then that won't happen/ Plus, when driving, you have a lot more airflow through the radiator which cools the engine faster.
That is where I would start. Replace the thermostat. Because this vehicle isn't offered in the US, I don't have the specifics. However, here is a link that explains in general how it is done. It should provide a good guide for you.
Let me know if this helps or if you have other questions.
Take care and God Bless,
Friday, March 12th, 2021 AT 8:03 PM