"Nine"

Translation: Náhástéi

[Judorange123]

Náhást'éí

[jtaylor162]

The pull-down still agrees with you, yet DL still dings this as a "typo" (not clear if it's mainly the tone on the final "i" or the inclusion of the apparently optional but clearly valid glottal stop (') that is incorrectly flagged in DL's software, even three years later (11/5/2021).

[MaxMonclai]

This is like with "hólǫ́" vs "holo'". The predictive text on my Diné keyboard says "náhást'éí" and Duolingo tells me the same when I don't add the glottal stop.