Using com.atlassian.jira.transaction.Txn class for transactions in an application. There ar major issues on one particural Jira Server version which is 9.8.0 (didn't exist in 9.7.1, gone in 9.8.1). Transactions are closed during execution, therefore results are not saved properly in the database.

Problem is caused by RequestLocalTransactionRunnableQueueFactoryImpl class, which in 9.8.0 version uses jiraThreadLocalUtil.wrap which closes any present connection.