Combobox loses items after entering multi-byte characters on IE and Edge

I have a trouble in combobox on IE 11 and MS Edge.
Though this problem does not occur on Chrome, the application is required to run on IE 11.

The problem is that combobox loses items after entering multi-byte characters like Japanese.

So our customers can’t filter items entering multi-byte characters. And also need to refresh page.

How do I deal with or workaround this? Please see an attached gif file.

Found on 8.3.0, and 8.4.4.

I’ve seen below forums and issues, but I don’t know how to do.

17162137.gif

I have confirmed this issue is fixed on version 8.5.1.
That’s great. Thanks Vaadin team.
17218521.gif