Problem with opened polygons in Grasshopper

Hi everyone! I’m doing a model in grasshopper, but I have some problems. As you can see, there are opened polygons that shouldn’t be there. Can anyone help me to fix it? Thanks in advance!! photo_2022-05-15_15-04-15|690x311

Many people can help but with just a picture it is not enough to help. Please read the advices in order to be helped.