Clearing the search in a grouped select does not restore all options

[vegegoku]

Describe the bug
After clearing the search in a select with grouped options, groups wont be populated with the original options.

To Reproduce
Steps to reproduce the behavior:

1. Create a select with multiple grouped options and make it searchable.
2. Search for an option.
3. select the option or clear the search.
4. Options wont be restored back to the original state

Expected behavior
Clearing the search should restore all options existed before the search