Not to split hairs. You are saying something important too, but… I’m an engineer by trade, so I think of “bugs” as defects in how software works. Like you click a button and nothing happens. Or you lose your progress. And I’d say in terms of software bugs, probably DuoLingo does better than LingQ. With its thousands of employees, that’s no surprise.
I could definitely add to your list of content-related DuoLingo complaints!