Isotrim brings back trimmed surface

Is there a way to completely remove trim data from a trimmed surface?

I am having this problem where, when I use isotrim, it seems to bring back the original trimmed surface. Is there a workaround to this?

In attached file it starts with a trimmed surface, then divides domain and runs isotrim. In the final isotrim output the surface has been divided, but showing the untrimmed surface.

TrimProblem.gh (10.1 KB)