Why do I keep leveling up without reaching the level?
Yesterday I was at level 9 in Portuguese when suddenly I was level 11, but it didn't give me the notification... is it just my Duolingo acting up? Because I did just one lesson and suddenly I skipped from level 9 to level 11...
Is it possible that you did immersion for one of your other languages while you were on the Portuguese tree? That has happened to me when I clicked on an immersion article link on my profile when my tree was set to a different language. Then the points count towards the language you are currently set to rather than the language the immersion article is actually in. For example, if I'm doing the Swedish course and a Spanish immersion article in my activity page distracts me and I translate a few sentences, the points I earn count towards my Swedish tree instead of my Spanish tree.