Focus problem with Select Widget

There is a bug in the SelectWidget.
While rendering the options using OptionWidget inside the Select Widget, if the property multiple is set to true you have to double tap in every Option to for selecting them.

Does someone know how to solve this?

Start by locating the SelectWidget and OptionWidget entry points and reproduce the issue with multiple set to true. Trace the focus and selection behavior while rendering options; done means each option can be selected with a single tap, with the behavior checked against the existing test setup if one is present.

Written by the indexing model from the issue text.