The quality of duolingo has gone down massively in the past few years as they have done lay-offs, they don't even have anyone checking the feedback coming from users any-more.
the courses themselves are worse too, designed more to stretch out app usage rather than teach more. I used to recommend duolingo as a good starter on learning a language, but it's just so bad now that I won't. And it seems to be a direct result of layoffs.