Bug when deleting text in front of @ sign

[Firefly 35]

When mentioning a user by the @ sign, when typing text in front of it and then deleting said text, the first letter is un-deletable.  For example, if I wanted to ask how rusty pins is doing but accidentally typed " @rusty pinsowg are you?", the 'o' would be un-deletable but the rest of the text would.  For now, I just click on a different page, return to the thread I was on, and hit "clear editor".  This can be annoying when typing a detailed reply and making an error towards the end. 

Hope Invision has a patch for this.