The transformation to “capitalise” is still not working in Beta 15.
Uppercase to lowercase works both ways, but after “capitalise”, lowercase will not revert the initial cap. And if you use “capitalise”, then “uppercase” it works, but if you then hit “lowercase”, your word will be capitalised again.
However, if you type the initial cap (with the shift key), both “lowercase” and “uppercase” work correctly; the “capitalise” command does something strange to the formatting of that initial letter.