No, duolingo, "Did you've supper yesterday" is not a correct English form. Let alone the right answer.
Unfortunately, I think contractions are done automatically by the Duolingo "engine" (without taking into account whether the verb is a helping verb or a main verb) and there's nothing the Welsh course maintainers can do about them.
Why isn't "Did you have dinner yesterday?" acceptable? Lessons up until now have taught that cinio/ginio = dinner
Dinner should be fine. Just report if it comes back around for you.
aiyo, can your engine decide or to forgo one to make known for everyone including myself sure got this issue one !?