Nintendo’s customer support account has revealed that a game breaking bug has been discovered in the charming Yoshi and the Mysterious Book which came to its attention thanks to user reports. The company outlined the issue below and said that it is preparing an update to fix the issue and asks for patience while they continue to work on a solution. Nintendo has apologised to owners for the issue.
We have received multiple reports that players are becoming unable to progress while playing ‘Yoshi and Fukashigi’s Encyclopedia.’ We are currently investigating the issue and have confirmed that it occurs under the following conditions: • Before hearing Fukashigi’s explanation of the ‘Index,’ start the Bird of Paradise investigation and finish it without making any major discoveries. • Afterward, if you listen to the explanation of the Index, you become unable to exit the Index page. *The explanation of the Index occurs after clearing a total of four chapters. We are currently preparing an update to fix this issue and will provide further information as soon as the update is ready. We sincerely apologize for the inconvenience and trouble this has caused, and we ask for your patience while we work on a solution.
Thanks to SonicGalaxy27 for sending in the news tip!

I am still at the first chapter so I guess it won’t affect me. I am taking it slowly.
I was taking it slow and I started to dislike it (I’m a completionist gamer). If that happens to you, I recommend just doing each creature as they come and not trying to 100% each one immediately. It’s kind of helped
Same here, I felt like I was in each level for hours. It’s fun to revisit some creatures and fully complete them.