Connection leak with Tomcat 8 using dbcp2 & ojdbc6 Oracle driver

Question

I have some troubles to fix connection leaks in our developement enviroment.

Im using: Apache Tomcat 8.5 server with:

• commons-dbcp2-2.1.1.jar
• commons-pool2.2.4.2.jar
• ojdbc6.jar Oracle driver
• Oracle client 12.1.0.2.0 64-bit

I have some resources declared as:

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/myApp">
  <Resource auth="Container" driverClassName="oracle.jdbc.OracleDriver" logAbandoned="true" maxActive="20" maxIdle="10" maxWait="1000" name="user1" password="user1" removeAbandoned="true" removeAbandonedTimeout="120" type="javax.sql.DataSource" url="jdbc:oracle:thin:@192.168.197.53:1521:orcl11g" username="user1" factory="org.apache.commons.dbcp2.BasicDataSourceFactory"/>
  <Resource auth="Container" driverClassName="oracle.jdbc.OracleDriver" logAbandoned="true" maxActive="20" maxIdle="20" maxWait="1000" name="user3" password="user3" removeAbandoned="true" removeAbandonedTimeout="120" type="javax.sql.DataSource" url="jdbc:oracle:thin:@192.168.197.53:1521:orcl11g" username="user3" factory="org.apache.commons.dbcp2.BasicDataSourceFactory"/>
  <Resource auth="Container" driverClassName="oracle.jdbc.OracleDriver" logAbandoned="true" maxActive="20" maxIdle="10" maxWait="1000" name="user2" password="user2" removeAbandoned="true" removeAbandonedTimeout="120" type="javax.sql.DataSource" url="jdbc:oracle:thin:@192.168.197.53:1521:orcl11g" username="user2" factory="org.apache.commons.dbcp2.BasicDataSourceFactory"/>
</Context>

Every time I shut down/restart Tomcat server, all connections between DBCP pool and Oracle DB (11g) stay open. I guess Tomcat should take care of that....

Any idea how to solve this issue?

EDIT: It seems its somehow related with the developers enviroment. On some computers the connections are closed, but on others they stay opened. We are using the same DB, the same Oracle client, drivers and the same Tomcat servers.