This bug was first reported on the spring side here
The sample project (that has to be deployed to weblogic) is available here (there are two projects actually, one with spring boot and another with plain spring mvc)
When using hibernate 5.1.x and 5.2.x in combination with Spring and Weblogic, the jta transactions appear to break.
Performing any type of database operation after a transaction was broken fails even if you specifically open a new one. Hibernate 5.0.x works perfectly fine.