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"]
include_blank doesn't seem to allow the validation to work.
[select* show-recipient include_blank "Patrickfirstname.lastname@example.org" "Conradoemail@example.com""Jenfirstname.lastname@example.org"]
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?