Bad loss spike when training nerfacto with high number of iterations

[hoanhle]

Describe the bug I'm training nerfacto on my dataset with 300k iterations (since I want to keep the original data resolution and it's 10 images 6kx4k). I know the standard is training for 30k but I could not understand the bad loss spike when training longer. Is this an implementation or configuration issue? Can you guys give me a pointer to solve this?