Flowable Timer Start Event not auto deleted when there is new deployment version

Hi Team,
We have upgraded flowable version from 6.4.1 to 6.4.2 and we are now facing an issue with the timer jobs. After deployment, old version timer jobs are not auto-removed and new version of jobs are being created. Due to this, there are multiple versions of timer jobs in the ACT_RU_TIMER_JOB table when there there should be only one version for each job.
Please help me resolve this issue. Thanks in advance!