Been trying to book with multiple airlines a DONE4 ex-CAI with DOH as the final destination and all of them have been unable to make DOH the final destination. Apparently their booking system is forcing the last segment to head towards CAI.
From my understanding of the rules, one can start and end a trip anywhere in the M.E.

My two questions are:
Has anyone ever faced this issue when booking with an airline?
Is CAI considered part of the M.E.? (When creating the same itinerary on the OW tool I haven't faced any difficulties)

(Tried with both QF and QR)

Thank you!