Duplicate orders created starting with 2.9.4

When I upgraded to version 2.9.4, I started seeing duplicate woocommerce orders created, including charging twice. After offering refunds, I tracked down the problem to the change made when upgrading from 2.9.3 to 2.9.4. When I downgraded the problem stopped. Today someone else accidentally upgraded to 2.9.5 and the duplicate issue occurred again, so I downgraded again. My setup uses the braintree gateway for receiving payments.