Found the root of this problem . In Purchase order, only the first item is being linked with Project, from second row of items we have to add project manually . Is this a normal procedure ?
Default behavior is say you enter 4 lines in your Purchase order and then you select a project for the first line, it will get copied over to other lines. However, if you already have selected the project in the first line and then you enter the other lines, it does not get copied over.