Multiple duplicate Jobs Created

If was running Nas Version on 5.3.1 in production and did get a huge
number of jobs with the same Configurations submitted. This must be the
behavior of https://sbforge.org/jira/browse/NAS-2614which was fixed for
Version 5.3.1 - the strange thing is, that I had not any problems in
Version 5.3.0.

Is anyone experiencing the same issue?
As suggested I set settings.harvester.harvesting.sendReadyInterval to
300 and I am using settings.harvester.harvesting.sendReadyDelay with
value 300

Also the HarvestJobManagerApplication dies with OutOfMemory Exception,
even when started with parameter -Xmx4096m

20:28:11.823 ERROR d.n.c.lifecycle.PeriodicTaskExecutor - Task threw
exception: java.lang.OutOfMemoryError: Java heap space
java.util.concurrent.ExecutionException: java.lang.OutOfMemoryError:
Java heap space
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
~[na:1.8.0_77]
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
~[na:1.8.0_77]
at
dk.netarkivet.common.lifecycle.PeriodicTaskExecutor.checkExecution(PeriodicTaskExecutor.java:171)
[common-core-5.3.1.jar:UNKNOWN_REVISION]
at
dk.netarkivet.common.lifecycle.PeriodicTaskExecutor.access$500(PeriodicTaskExecutor.java:47)
[common-core-5.3.1.jar:UNKNOWN_REVISION]
at
dk.netarkivet.common.lifecycle.PeriodicTaskExecutor$1.run(PeriodicTaskExecutor.java:152)
[common-core-5.3.1.jar:UNKNOWN_REVISION]