I saw it in the fundementals 2 level. Here is the snapshot.
It is the shockest glitch that i have never even noticed. What cause this??? I have no idea
There are some puzzle that you can skip, I think this particular case is not a glitch at all, but one of those skippable puzzles.
Yup, we’ve recently rolled out a new feature allowing users to skip puzzles (with the exception of puzzles in the final topic of any course).