The selected item is 'disappear' if scroll down/up then scroll back

[victoriazhaoyan]

Bug description:

When we scroll down or up to the 'selected' item in the dropdown,
then scroll back again, the 'selected' item is 'disappear'.
and will 'appear' again if move the mouse.

Link to minimally-working plunker that reproduces the issue:

http://plnkr.co/edit/1Okumk?p=preview

[Replicated Steps:]
I recorded a video for showing the replicated steps, please following the link below:
https://www.screencast.com/t/fRkHlqvXkv1G

Step 1: Open the dropdown, choose one item (let's say 'ten')
Step 2: Click 'arrow' to open the dropdown, move scrollbar to bottom,
Step 3: Move scrollbar back to the position of 'selected' item (e.g. 'ten')
**Actual Result: ** The 'selected' item is 'disappear'. if you move the mouse, the 'selected' item is 'appear' again.
Expected Result: The selected item should be displayed.
Note: this issue can be replicated on Chrome, CANNOT be replicated on IE 11.

Version of Angular, UI-Select, and Bootstrap/Select2/Selectize CSS

Angular:1.5.6

UI-Select:0.19.8

Bootstrap/Select2/Selectize CSS (if applicable):
No. No any theme is applied.

[amitusasane]

Hey, I am also facing the same issue. Any solution/suggestion on this?