Have you tried to unfold the song into one large chorus, assuming of course that it is less than 255 measures; that is the limit in the Win versions, don't know about the limit on the Mac version. If you can try it, make your tempo changes and determine if they stick.

Also try your tempo changes on another song with more than one chorus to determine if you have glitch in your initial song or if you have found a bug in the Mac version.


Principal: Your child always causes trouble in school.
Me: My child causes trouble at home, do I ever call you?

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware