New practice frustrations: Select the article
Another thing that's changed with the new update: the "Select an article" exercises have changed their order. See:
I don't know whether this is a result of the phone version displaying them randomly or in a different order, but the web version has always been consistent. It means it's much faster to select the article (you don't have to think about mapping the article to an arbitrary number on top of working on the language skills).
This is a pretty basic issue which doesn't require much effort/time from a development perspective but causes users a lot of unnecessary frustration. There are a number of these (and have been for years). It gives the impression that the Duolingo team don't actually use Duolingo Web much. Hallway usability etc.