I unlock a volunteer and I drive away. After that I click the volunteer button, voila, boom.

I did as follow:

1. Unlocking the village with the volunteer

2. Leaving

3. Clicking the volunteer button.

If you can't understand me you can let me explain better, taking pics etc.

BTW really enjoy the game, waiting forward to the end for the war.

Looks like a bug. I'll check it out.

Thanks for reporting it ;)