I am trying to book ORD-SIN-MAA-ORD as a roundtrip award travel with a stopover in Singapore. Since this is a roundtrip reservation I am eligible for a free stopover.
The routing i found is as follows
ORD-AMS-SIN : Dec 17
SIN-MAA : Jan 1
MAA-BKK-SIN : Jan 18 reaching SIN at 11:15 AM
SIN-ORD: Jan 19 leaving at 6:15 AM

When I called in to make the reservation I was told that since the return leg had a layover of more than 5 hours in singapore (since I land at 11:15 AM and dont fly out till 6:15 AM the next day), it is considered a stopover and will not be allowed as I already have one stopover in the roundtrip.

I have not seen any such rule. I was under the impression that as long as you are under 24 hours it is not deemed a stopover. Is the agent correct?

I can price both the ORD-SIN and the MAA-ORD segments separately online with the correct number of miles. However the online system is not sophisticated enough to let me include the SIN-MAA to make this a rountrip with an eligible stopover.

Suggestions?