Strange results on the Lego dataset

[honghd16]

Hi, thanks for sharing such great work!
I followed the instructions to install dependencies and place datasets.
Since I only wanted to see the results for the Lego in nerf-synthesis dataset, I modified the scripts and only make the lego line remain.
It runs all good but the results after the 8 views train and ft are strange, just like this.

Could you tell me where is the problem?
Thank you very much!