Inconsistent/unpredictable XP scoring
It's been quite difficult to figure out what's going on with all the recent changes - can't tell what's a bug and what's a feature that I don't understand.
Unpredictable XP scoring does seem to be a bug, though (or at least a poorly-designed feature). On the web app, I get the maximum score (10 XP) much more often than on the mobile app, which seems to be far more strict.
Perhaps more importantly: how does Duo decide when a lesson needs reviewing? If it's awarding me only 5 XP, doesn't that mean Duo should have waited longer before putting it up for review? I think it has to be consistent: either lessons only go up for review when they're worth 10 XP, or the tree should show me how much each lesson is worth. It becomes annoying when you're defending a long streak and can't tell if a given lesson will give enough XP to hit your target.