Score loss question

Thank you for the great work. I'm currently trying to use PointGoup on my outdoor data but got the score loss looks like the image attached. Could any please help to understand what could possibly be wrong with this?

Thanks.

<img width="272" alt="Capture" src="https://user-images.githubusercontent.com/25648942/152698647-1376d848-ec92-47e0-b31a-e83b59ccb5f1.PNG">

