Rel strategy not triggered if PO edited in ME53N

Dear all,

If PO is edited in ME21N,ME22N or ME23N, Release strategy is triggered in PO.

But, if PO is edited in ME53N  (by selecting radio button PO in option other purchase requisition in ME53N), release strategy is not triggered.

The rel strategy tab disappears.

I want to know whether this is standard functionality of SAP.

What can be done to avoid this.

I have removed the authorization of ME51N and ME52N from specific user IDs.

I cant remove authorization of ME53N as purchasers need to check PR against which PO is to be raised.

Please suggest how to restrict users to access POs through ME53N .

Thank you.

Sampada Desale