Ice not tracking mark and insert

[subinsunny]

Steps to reproduce:

1. Select Some text
2. Edit Some text

I am using ice plugin with tinymce and everything is working fine except when I try selecting some text and insert other text, the new text comes out of the insert tag(<p>newText<insert></insert></p>) and there is no delete tag with the old text. I tried the same on http://nytimes.github.io/ice/demo/ but here I do not face such problems.

Environment
Google Chrome-v56.0.2924.87
Tinymce-4.5.2