Region difference randomly not working in grasshopper

Performing region difference on series of curves but one region it will not work for. I’ve compared the data of the curves that do work and the one that doesn’t and everything looks fine. I’ve baked it and referenced it and still will not work. The only option at the moment is to bake the curves out and use the trim command in rhino but ideally want to stick to keep it all in gh.

Could this be a bug?

Can you post your curves? I’m leaning towards a tolerance / curve creation, but hard to tell without geometry.