onPickerValueChange is not triggered on first click on panel column's first item

[zxsure]

Use Time Picker and value set to null.
Use format: 'hh:mm:ss' or with 'a'

click into Time Picker and after panel opened.
Try to click on each columns' first item '01' or with 'a' it's 'AM'

Result : onPickerValueChange is not triggered.
Expected: onPickerValueChange should be triggered.

Not happen if click on non-first column item.

[zxsure]

@afc163 just found another issue, please help to take a look, thanks.