Found a bug related to individual skill practice
When I click strengthen for an individual skill (as opposed to through the global big blue strengthen skill button) I get asked to choose "Start timed practice" and "Practice without a timer".
Even if I choose neither options and go to "Home" without seeing a single sentence or word from that skill, (then refresh with CMD+R on the 'Home' page where the skill-tree is) the skill turns gold.
So without any practice whatsoever Duo still thinks that I have practiced.<h1>Expected behaviour:</h1>
The skill should stay as it was instead of turning gold if no practice took place.
I've noticed the same issue too, and I've also noticed that sometimes when you go to strengthen individual skills, it'll only give you a very small number of exercises to complete, definitely not enough to justify marking it as decayed, and that's it. That's a great way to get XP and lingots easily, but it doesn't really help with language learning.