Helix issues

While l feel the helix is currently more effective than others in my collection, lm having issues with keeping it in place.

basically from what lve read here and seen in a posted diagram in another thread (this image), l cant seem to keep the helix from being dragged in completely, according to the image it should only be inserted to the final ridge keeping the thinnest bit at the bottom outside, but for some reason no matter the position l am in it just seems to drag in all the way.

lm contemplating modifying some sort of rubber stopper of sorts to kind of keep it from going all the way in, however lm wondering if any others had this issue and found a way to get around this kind of issue, that being said it would be interesting to know any tips for this model to get the best out of it.