Audio tracks to follow tempo changes

Hello everyone,

I'm really confused about something on Garage Band for iOS. Currently using an iPad Pro 12.9 with iOS 9.3.1.

I started a new project, captured a drum loop from another app (Anytune Pro in this case) and trimmed the loop so I could loop it and practice on top of it.

I changed the tempo of the project and the audio followed the tempo change of the project in an "elastic audio" way.

What's happening now is that I tried doing it again, and the audio tracks do not follow the tempo change anymore! I don't know what I did different, I tried to replicate it several ways but it just doesn't work...

Here's the link for the session, you can open it in your iOS device and change the tempo and you'll see that the drum pattern (the salsa one) will match the tempo of the session.

https://www.dropbox.com/sh/swbfnj24qbuzhmn/AABSGk-zwc1GlMqxlYTMAhQda?dl=0

If anyone can help me out and explain how to make audio tracks follow tempo changes, I will be very grateful! Thank you very much!!