Distorted corners issue while using cloth modifier


I have two cubes which were divided using the divider plugin. However, when I apply ‘cloth’ modifier on one cube, it gets perfectly thickened. However, when I apply this modifier on another cube, it begins to stretch from its corners. Why is it happening and how can I ensure proper thickening of the cube faces?

Here’s my c4d file.

I’m following this tutorial from which I got the cube which was split nicely. Eventually in the tutorial, these kind of results are generated. The tutor doesn’t describe the detailed process of this in the video and skips some steps.

I am enclosing the original file shared in the course. I have not been able to figure out the clean extrusion of cubes.
for forum_blocks.c4d (4.0 MB)