Trim issue with plan

I’m having a bit of an issue with the trim tool in Rhino 7, where if I select the area at which I need to trim, it trims certain, seemingly random, segments of the curve, instead of trimming before the intersection of the curves. I’ve tried rebuilding the curve to (2,1), (showends), and (insertknot), none of which really solved the problem. Sorry if this issue is a tad insignificant. Any help would be much appreciated.

My highlight is cyan. The image to the left is during trim, to the right is after one trim. The idea is to trim between the wall and cladding layer.
I can attach the file if necessary

Yes, it would be good to see the file…

TrimExample.3dm (386.1 KB)
As requested, sorry about that.

From your description, I’m not quite sure what you want to happen - something like this?

Yes, That is precisely what I would like to happen. Sorry about the poor description.

OK, took me a minute to reproduce the problem. Inside the trim command, set “Extend cutting lines” to No… then it works. See video below. Note, your wall is poorly offset, there are overlaps or gaps, but it still seems to trim correctly.

Ahh that would make alot more sense, thank you very much. Yes the offset line isnt finished because it’s meant to be a boundary for the trim. After I trimmed the curve it would be deleted after. But thank you very much once again. Sorry if it was too much trouble.