I can't seem to find an answer to this but the mechanic of donating to shrines has been bothering me for a while and I know I'm not alone.
If I can donate, say, 3000 worth to a given Giant in a day and at one time but am only 1000 away from getting an emblem, I have to donate in two batches or the leftover 2K doesn't register. I get the iMG from it but am left with 0 favor.
It's not game breaking and I can juggle the math and the extra EHSP but it is puzzling to me.