Hello,
I have a very weird interaction in some monolithic stairs
The stairs are designed by sketch.
I'm attaching two screenshots

This picture is showing the issue i'm having, the stair is completed no errors pop up but half of the stair is missing in 3d.

In the second screenshot you can see the same sketch and all that has been changed is the direction( flip direction)
Any info on how to solve this would be higly appreciated.
Thanks in advance