level and review functions
I think something is wrong with the Duolingo innards for Esperanto. Since last evening I've been kicked out of quizzes i was in the middle of, told I've strengthened skills i was not reviewing and getting messages that I had reviewed a skill while working through a new lesson. For instance just know I was told I had just strengthened Animals while doing the 2nd lesson of questions. It did however show that I had completed lesson 2. Is this an engineering issue?
I can't speak for getting kicked out of lessons, that does sound like an issue, but you will sometimes successfully strengthen one lesson while practising another, because the words in one lesson come up when practicing another lesson. The "Questions" lesson seems to get this a lot, I presume because words like ĉu kiu kio kie come up in a lot of other lessons. That's not something to worry about.
Being kicked out of lessons OTOH does sound like a bug in the machine.
there was no animal vocabulary in the lesson. I had just previously tried a generic strengthen skills that was very long (over 40 questions) and did include a bunch of animal vocab, along with other grammatical items and it finished off only strengthening one of those (which specifically i do not recall).
If you look at the vocal taught in the animals lesson, it isn't all strictly animal related. You have flugas, vivas, nokte, ido, ovojn, Duo, kaptas, etc, all of which can be used in plenty of sentences besides animal related ones. It might be that your strengthen skills took you right to the edge of having strengthened that skill, and then a couple of not obviously animal related words came up in your questions lesson, if that makes sense? I am just guessing based on my own experience, though, I don't have any insight into the techy side of things.