Please log a Support Incident and we will be glad to. The Analyst can take a look at the data and see what is going on and log a bug if necessary. I have not had any issues with the using of Breaklines in TINs.
Any progress on this? I'm running into the exact same problem.
Had the same problem and have a workaround regarding using the ERASE function. Instead of using ERASE, I created a polygon shapefile that was the inverse of what I wanted to erase and just used the CLIP tool to keep everything I wanted. The rest was removed without issues. No more pesky relict breaklines.
So instead of having a feature of what you want to remove, you need a feature that will overlay everything you want to keep.
It's clunky but I hope this helps!