It is taking the "Next Line" setting for function method blocks. The editing code isn't taking that particular setting into account. Even if you have "Beautify with typing" enabled, this won't do what you want, because it's conservative in the way it's implemented. It will never look at a method, and say "Hey, this is only one line of code, so lets pull it and the braces and the declaration up onto one line." It's more along the lines of you telling the beautifier "I'm going to do this, don't screw it up for me."
It is irritating when typing one-liners, having to manually fix up the method. One thing I've considered is having a command that could be bound to a key that can cycle through the styles in place: one-line function/block, then then through the other brace styles, finally back the default brace style.