I was recently told of a supposed bug that wouldn’t allow the user to progress to level 3. I have tried multiple times, however, I am unable to recreate what they describe. Because of this, I am going to assume that either they did not have enough stars to move forward, or they did not complete the preceding level.

tl;dr
make sure you have enough stars, and you have to beat a level to move onto the next.

If you are the person who informed me of this bug and are sure that it was not actually because of the above reasons, please submit a bug report with the necessary details https://goo.gl/forms/AO2XMnfn09XxBLXQ2