I've had a recurring problem with Magical failing to replace shortcuts with the expanded text. It happens most often filling out forms (which I have to do a lot in my work). As an example, "nnn" is supposed to type my name, "eee" is my e-mail address, etc. But sometimes I type "nnn" hit Tab, and... it leaves "nnn" behind. I usually catch it, but it's embarrassing when I don't.