We are still having issue on data approval

Dear all

We are still having a serious issue on data approval on version 2.17 where We had approved data in dhis 2.16 where all data set was locked,and after upgrading to 2.17,all dataset became unlocked.Now users can Modify the data what ever they want.I have raised this issue many times but yet i’m not getting any help.

I’m still waiting if some one can help on this issue.