Using the same fiddle used in #87 (https://jsfiddle.net/chphr0ab/3/) I see some odd behaviors when trying to insert mentions in to existing text.

To Repro:

• Type "@p" and select "Phil Hartman"
• Continue to type "test1 test2"
• Try to insert a mention in between test2 and test2 by adding an extra space before test2 and typing "@"
  At this point you see the cursor pushed to the end of test2 and when you try to add a mention it doesn't work properly.

Here is a video demonstrating the behavior: https://www.screencast.com/t/pgsbgbwlhi2t