Replacing Italicised text causes incorrect insertion position.

[jamesey2001]

Visit the demo page:

https://www.loopindex.com/lite/demo/

1. Highlight the word "Welcome" in the editor.
2. Click the "I" button to make it italic.
3. Highlight the letters com from the italicised word.
4. Type in any character ( i.e. z )
5. com becomes struck thru but the z character is inserted at the start of the word, i.e
   zWelcome instead of Welzcome

Further steps,

6. Try the same with Underline, Strike Through, Subscript, Superscript
7. Same results as above, the insert position jumps to the start of the applied style.