Unexpected discontinuity/hole in volume


I am trying to webcut the rectangular volume with the two sheet surfaces in the screenshot. One of the webcuts the volume just fine but the other one does not and the volume ends up having a discontinuity (hole). Is there a simple fix to this problem?
See the attached figures. Here’s the section of the code that does the cutting:

webcut volume 6 with sheet body 1
webcut volume 8 with sheet body 2
delete body 1 2
imprint all

Thank you,

Screen Shot 2020-04-09 at 2.06.42 PM.png
Screen Shot 2020-04-09 at 2.06.53 PM.png