Hello,
Sorry to hear about the inconvenience.
We have confirmed from the Development Team, the functionality of the Search Form has been changed to fill-out the field as mandatory to be in-accordance with the WooCommerce functionality because this is how the default WooCommerce Search form works.
But for your ease and convenience, they have confirmed that in the upcoming Theme Updates they will add an ability to revert back to the previous state, like you mentioned.
So, for the time being please get along with this new functionality and in the upcoming Theme Updates, you will get the functionality that you mentioned.
We appreciate your patience, understanding & cooperation in this regard.
Best Regards