Training doesn't work / converge for Blender - chair dataset

Hi, I followed the install instructions and tried training for the chair data in Blender. However, it never converged and just output white background. The PNSR just bounced around between 13-14 for 13 epochs. Did anybody else experience something similar with this dataset or others? Thanks!

Start by reproducing the reported training run from the install instructions with the Blender chair dataset, recording the PSNR and rendered output across epochs. Compare the run configuration and dataset processing with any available examples; done means identifying a reproducible cause for the non-convergence and documenting a resolution or confirmed dataset limitation.

Written by the indexing model from the issue text.