The first item of selection list sometimes get highlight

when I select Japanese input and enter A `あああ` at first, the `あああ`  didn't highlight in the selection list

then if I select(click) the first `あああ` and enter it again, the `あああ` got highlight in the selection list.

the highlight of the first item disappears when I commit the pre-edit text by the Enter key or click the second item in the selection list.
The expected is to clear selection when starting a new input after the last commit. 
And it is strange when I click the second item the highlight is disappeared, which means this shall be a bug of clear selection, it seems the index of selection didn't reset when it is 0.