### Bug report

When the virtualization is enabled, in some cases, the selected options in the dropdown do not match the selected options in the input. 

### Reproduction of the problem

1) Create a MultiSelect with Virtualization (for example, the same configuration as in the online demo).

2) Select multiple options from the dropdown.

3) Enter a search entry in the input to filter the displayed options and select a specified option.

4) Scroll down and select another option.

5) Remove some of the already selected options through the input.

6) Open again the dropdown. The selected options in the input do not match the selected options in the dropdown.

A screencast for reproduction: https://app.screencast.com/v6GtyST0dQAnh

### Expected/desired behavior