Credit Document coming in VKM5 but not VKM1

Dear SAP Gurus,

I have configured credit management at delivery and PGI level at my client. I am getting an error that credit limit has been exceeded which is correct

correct as per the configuration. Now, The problem is I have developed one Z tcode for approval where we call the standard T-code  VKM1 which is the tcode for blocked SD documents. In some of the cases we are able to see blocked documents(delivery) in VKM5 but not in Ztcode(which calls VKM1). This is happening in few cases. Can anyone help me with this behavior.

(Credit check error snapshot)

Thanks in advance,

Rohit