As shown in the picture below, thermal impedances of an IGBT device depends on the temperature. However, there is a strange phenomenon as follows. While with increasing the temperature, steady-state impedances will increase, but you can see that at a low time some low-temperature impedances become larger than high-temperature ones. Why?
Note: We can model such impedances by resistor-capacitor circuits. Do we have the aforementioned phenomenon in RC circuits, namely lower value at a low time but higher value at a high time. How can justify this?

[![enter image description here](https://i.stack.imgur.com/Ajgmi.jpg)](https://i.stack.imgur.com/Ajgmi.jpg)