You want the ambient temps to be higher; so if it is basking all the time then the ambient temp is too low. In the wild they dont sit in the sun for hours; its too hot. Temps are a huge part of proper husbandry; anything away from proper husbandry will start to cause stress and lead to bad things.
Check a weather website for seasonal averages in PNG; it doesnt get that cool at night.

Hope this helps.
miz
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Mizzy: frilldragon.com