The camel-jpa JpaTransactionManager does not work as expected with mixed transaction and rollback scenario

Issue

Default camel-jpa JpaTransactionManager does not work as expected with mixed transaction and rollback scenario.

camel route

    <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
        <route id="parent-route">
            <from id="route-timer" uri="timer:foo?repeatCount=1"/>
            <transacted id="transactionA"/>
            <log id="_log1" message=">>> call rollback-route"/>
            <to id="_to1" uri="direct:rollback"/>
            <log id="_log2" message=">>> call commit-route"/>
            <to id="_to2" uri="direct:commit"/>
            <log id="_log3" message="done"/>
        </route>
        <route id="rollback-route">
            <from id="_from1" uri="direct:rollback"/>
            <onException id="_onException1">
                <exception>java.lang.Exception</exception>
                <log id="_log4" message=">>> rollback-route's' onException block. mark rollback"/>
                <rollback id="rollbackA" markRollbackOnlyLast="true"/>
            </onException>
            <transacted id="transactionB" ref="PROPAGATION_MANDATORY"/>
            <process id="_process1" ref="myCarProcessor"/>
            <to id="_to3" uri="jpa:io.fabric8.quickstarts.camel.Car?usePersist=true"/>
            <throwException
                exceptionType="java.lang.IllegalArgumentException"
                id="_throwException1" message="Forced"/>
        </route>
        <route id="commit-route">
            <from id="_from2" uri="direct:commit"/>
            <onException id="_onException2">
                <exception>java.lang.Exception</exception>
                <log id="_log5" message=">>> commit-route's onException block"/>
            </onException>
            <transacted id="transactionC" ref="PROPAGATION_REQUIRES_NEW"/>
            <process id="_process2" ref="myBicycleProcessor"/>
            <to id="_to4" uri="jpa:io.fabric8.quickstarts.camel.Bicycle?usePersist=true"/>
        </route>

There is no data in DB.