ERS Partial Receipt Settlement - not postable

Hi Experts,

I'm trying to activate our ERS and to test it. When I receive fully all seems to run smoothly. When I do a partial receipt and then run MRRL, the settlement is not "postable". I then do the remainder of the receipt so that it is fully received. I see both of the partials in MRRL but it still says it is not postable. Any suggestions on what I may be doing wrong?

Also, I noticed in my testing that I was able to do a MIRO for an ERS PO, but the MRRL still picks up the GR to settle. Is there something I can do to prevent the MRRL from picking up a receipt IF a MIRO was already done?

Cindy