Cell Profiler recognized worms on some images, but not others

cellprofiler

#1

Hello,
I wanted to quantify my images of C. elegans stained with Oil Red O (red stain). I run the pipeline and the worms were recognized (outlined) by CP on some images, but not on others. Those come from the same run of microscope.
I am attaching links to examples below.

I don;t understand why CP would be able to recognize worms on some images but not on others, especially that they seem to look similar.

https://drive.google.com/file/d/1zUNfjMBWwWLdu10azDLYpwsToyowrZHb/view?usp=sharing
https://drive.google.com/file/d/1jP6FJm_hY4e1sVtsBXZIs0Ada-sg1DER/view?usp=sharing
https://drive.google.com/file/d/1-LYsbcP5MoxKDjZzyvjeiTrLtQ3yG1q2/view?usp=sharing
https://drive.google.com/file/d/1ubVG1p_swTn9a_9NnNQFJwvZMi0JCoUD/view?usp=sharing
https://drive.google.com/file/d/1e-IVKfOCeUDtjByeUZY1eBbuGPBy2Msi/view?usp=sharing
https://drive.google.com/file/d/1nciMecRf_CtbwLYCqX6VcfqSkvHvNA1S/view?usp=sharing
https://drive.google.com/file/d/1qX6ouUIFVE6prFqesco_LP5y21OxVyJk/view?usp=sharing
https://drive.google.com/file/d/1sG11xayzQXCdREr_DxPoh2pX7y0YCYjL/view?usp=sharing
https://drive.google.com/file/d/1RULS0I6J0XA6Ni1BIfT4cAf-TDHKYVmV/view?usp=sharing
https://drive.google.com/file/d/1JeKpI_Bc5nI93YiuVrU0QSg47qHwjSKq/view?usp=sharing