Making Dropdowns required

Can’t seem to find too much about this problem but noticed its extremely difficult to make a dropdown form required with Contact Form 7.

The only successful scenario seems to be requiring the select, and making the first option blank.
[select* menu-596 "" "Item 1" "Item 2"]

Using include_blank doesn’t seem to allow the validation to work.
[select* show-recipient include_blank "Patrick|pjohnson@enkshows.com" "Conrado|cvillazor@enkshows.com""Jen|jpun@enkshows.com"]

Using the listo extension also doesn’t allow for a required state.
[select* location-state include_blank class:input-120 data:us_subdivisions.states]

Considering this, it seems a bit off? Maybe I’m executing incorrectly?

https://wordpress.org/plugins/contact-form-7/