Question about rv!record

I have built a interface for recordtype A to show summary, recordtype A has several recordtype B,C,D...related to it, but I found when I am viewing summary for related record B, it only shows 10 items, even though it actually has 20 items. I changed the grid's pagesize to 20 and can still see only 10 items. Is there a limit when we pass rv!record and the related records only has 10 rows at max?