Input not keeping focus during multi-select

[Tac Tacelosky]

I'm using select2 version 4.0.7 (yarn add select2), and when I allow multiple selections in an input field, the behavior is not as expected (or as it was in a previous version).

When I enter the field, I begin typing, and see the dropdown list. Then I press <enter>, and the field is added to the select box, BUT I lose focus.  To add another element to the select box, I need to mouse back to the field.

Hitting <tab> when the list is displayed is worse -- the list goes away, and nothing is added to the field.

I upgraded to the latest library when moving to webpack encore, so it's certainly possible I'm configuring something incorrectly.  Any suggestions on how to solve this?

Thanks,

Tac