I was recording my electric guitar into garageband, I noticed I was recording in a different track so I deleted the recorded track, then that action suddently changed the length of my audio files. I hit the exit button, clicked dont save, and then re-entered to see if it was just a bug. When I re-entered, a pop up message said 51 audio regions changed in length with no explanation. Has anyone who uses garageband to track instruments had ths problem? How can it be fixed. (Also, I had this issue many times, but in all those times only one or two audio files were changed, not 51 times like now. And I already tried restarting my Mac.)
With a bit of luck, you can undo those actions that caused your issue with CMD+Z (repeat it until you get the deleted track back).
The only other thing I can think of, is that your projects' BPM changed. If the BPM is increased, it will also speed up all audio- and midi parts, making them appear shorter. But I am sure you would have noticed this as the tempo changes and everything sounds faster.