Tadpoles / Slope Signatures only work for the first corridor per piece of geometry

I have been trying to figure out when my slope signature annotation is so temperamental. It sometimes works and sometimes doesnt work. I've even had it work, then i've removed the annotation, tried to reapply it and it not work when nothing at all has changed. I've tried to find the issue through process of elimination by checking, the annotation groups, templates, feature symbology and geometry i'm using. I've also experienced it only annotating part of the template length. I've also played around with the line lengths and offsets in the annotation group to try and solve this issue.

This investigation has led me to discover that the annotation only works for the first corridor of any given geometry. Please watch my video below demonstrating this. Can anyone help me with resolving this issue? https://youtu.be/Z3ueJfHYAMo