Problems processing returns with authorize.net

Hi i use the plugin created by the NOP team on my site. I am able to process orders and everything syncs to my merchant account but not for returns. We seem to always have to go process the returns manually in our merchant account on authorize.net.
Is this normal? The previous plugin we used with PayFlowPro before we upgraded to NOP 3.90 from NOP 3.00 was processing the returns as well.