Quick Fix Terms and Conditions

modify-functions.php

<?php
	add_action( 'woocommerce_after_checkout_validation', 'digthis_two_step_checkout_validate', 9999, 2 );
	function digthis_two_step_checkout_validate( $data, $errors ) {

		$step = filter_input( INPUT_POST, 'current_step' );

		if ( empty( $errors->errors ) && $step == 'step-1' ) {
			$errors->add( 'digthis', __( '<span id="digthis-prevent-error">Digthis Error</span>', 'woocommerce' ) );
		}

		if ( wc_terms_and_conditions_checkbox_enabled() && empty( $errors->errors ) && $step == 'step-1' ) {
			$errors->add( 'digthis', __( '<span id="digthis-prevent-error">Digthis Error</span>', 'woocommerce' ) );
		}

	}

	add_filter( 'woocommerce_checkout_posted_data', 'digthis_validate_terms_and_conditions_first_step' );
 	function digthis_validate_terms_and_conditions_first_step( $data ) {
	    $step = filter_input( INPUT_POST, 'current_step' );
 		if ( wc_terms_and_conditions_checkbox_enabled() && $step == 'step-1' ) {
		    $data['terms'] = 'on';
	    }

	    return $data;
    }