wrong amount posted in journal comparing miro

Dear experts ,

i have a problem in amount of journal of MIRO

when create miro for muliple PO's [2 Po's ]with 2 material referred for 2 material receipt the application calculate the materiel price different for price appear in invoice it created based on price for line number 1 . but when viewing the screen it will appear in correctly price .

by check for problem i found that document reference for line number 2 changed to document reference for line number 1

is there any clarification for this problem .