Not getting XP from a lesson
I am a fairly regular user of Duolingo and sometimes, in the end of a lesson, my progress won't be saved and I won't get the XP. I just answer the last question and it will grade it, but that's it. Nothing happens. My screen will just show the graded answer. If I go back to my tree nothing has changed.
Is there anything I can do to avoid this? It degrades the quality of the learning experience.