Blocked date typed into a DatePicker is recognized as a valid date (calendar is losing focus and date is selected))

[EddieJostell]

react-dates version
react-dates@18.3.1

Describe the bug
Manually typing a blocked date into DatePicker makes a blocked date become selected.

Steps to reproduce

Step 1: 
Go to the playground.
https://airbnb.io/react-dates/?path=/story/sdp-day-props--blocks-fridays

Step 2: 
Manually type 02/28/2020 into Datepicker input field. (a blocked date).

Step 3:
Calendar is losing focus and a blocked date is now selected in the calendar and input field.

Desktop (please complete the following information):
Possible to reproduce on desktop.

Is the issue reproducible in Storybook?
https://airbnb.io/react-dates/?path=/story/sdp-day-props--blocks-fridays