Here is logic from post #1637:

International Connection vs Stopover for AA OneWorld Award:
(can be different from logic used by Airport/Country to calculate Taxes)

if layover <= 6hr then
it is connection
else if layover > 24 hr then
it is stopover
/ * you come to the next part of logic only when layover is between 6 and 24 hours */
else if you are catching first SCHEDULED flight then
it is connection
else
it is stopover (irrespective if earlier flight has availibility or not)
end if


Current OW schedule shows afternoon flight on DOH - TXL sector for 4 days and morning flight on the other three days. So I doubt "a prior scheduled flight with no availibility" is making it is a stopover. Possible that agent is looking at overnight stay and interpreting as stopover. (given that same agent thought that flight with AA was needed, might indicate that agent may not be fully familiar with all rules of this award)

The standard protocol is to put as many flights as possible on hold. Politely thank agent (so that s/he does not add any negative comments on your booking) and call again. US day time seems to be better chance to get knowledgable agent than US evenings/night)

if you let hold expire then seats may or may not go back to award inventory.

good luck.

PS: If your paraents are taking first IST - DOH flight that arrives in DOH late morning and instead of taking same afternoon connection to TXL, if they are opting for taking next morning's flight to TXL then agent is correct that this is 20 hour layover is stopver as per logic above.

Do let us know how this pans out.
Thnx