KML Altitude Deviation

The altitude in my flight path deviates by approximately 500meters when imported with this tool, it does not when looking at the kml file in different software e.g. Google Earth Studio:

<img width="1133" alt="Image" src="https://github.com/user-attachments/assets/ba51f135-417a-4d5f-bb58-a0f0c5f9a148" />
KML:
https://www.dropbox.com/t/pEf2KCpMgveB3R5U