Slicing Corridor makes some solids dissapear

Hello,

I want to update you on an issue I am facing. I have extracted cut and fill solids from a corridor surface to the existing ground. However, when I try to slice these solids using Dynamo, some of them disappear.

I believe this is because there is a region gap in the corridor due to a cross bridge, and the extracted solids also have this gap. To solve this problem, I manually sliced the solids between the gap, but when I ran the script again, the solids again disappeared after the gap.

I tried to select the solids after the gap (in the script), but they either disappeared or became very unusual large rectangles. Unfortunately, I couldn’t take pictures as the script took a lot of time. I have attached a few screenshots to help explain the issue.

Additionally, I am splicing the solids at 20-meter intervals to prepare them for 4D.

Thank you for your help.