Evaluation step with custom dataset

[jeylisitsa]

I ran into an interesting issue. When using a custom dataset (both with custom.json and custom_alt.json) I get only up to 5 frames in my test_renders. This happens independently from the original image dataset size (tried range from 35 up to 90 images).
Has anyone else encountered this issue? Are there any settings I can tweak in the code or do I need to try a bigger dataset?