BBcodes Signature Not Working

Hey guys, I'm using the "BB Codes Button Manager" addon instead of the default Xenforo buttons. BbCodes & Buttons Manager

However, whenever I try to use the "Image" button to insert an image and press "Save", the image never saves on my profile. However, when I use smilies, text, etc., it saves. Is there any reason why I can't insert an image in my signature with the addon?

Here's some pictures of it as well. Thanks! :)