Two problems with the word endngs: A) Samia is a feminine proper noun, and as such, doesn't receive a final -n (as a dipartite noun). And it's in the nominative, so it takes an -u, not an -i. Saamiiya(-tu). And B) Jayyida(-tun) is in the nominative, not the accusative, so it takes -un, not -an.
Totally agree with you. However, the last ending should not be pronounced at all as it is the end of the sentence.
Best thing to do would be to report it to Duolingo as a bug so hopefully they will fix it. You can report it here: https://support.duolingo.com/hc/en-us/requests/new. I'll report it as well.