Just got off the phone with the international reservations desk with an agent who told me she had been on the 1k desk for a long time.

I was trying to book the following:

IAD-FRA-BKK-CNX (open jaw)
HKT-BKK-FRA-IAH (stopover)
IAH-IAD

She told me that I couldn't have both an Open Jaw and a Stopover on the same round trip reservation. Is she correct?

I'm going to call back for a little call center roulette, I guess, but I was thrown off by her insistence that this wasn't a legal routing.