Horrible audio export

[ptriq]

Hey, I'm a newbie on AL12, trying to make some music mashup mixes as a DJ. I Created a mashup where I use some tempo change automation. When playing from the interface I hear cracks and drops of music. The export gives me the same result. I'm on a brandnew Mac Studio M2 ultra with 64GB of memory. (An M2 Ultra has 24 CPU cores, 1TB SSD...) Sonoma 14.4.1, AL v 12.0.2
I played already with settings/audio/buffersize setting it to anything from 32 samples to 1024 samples but that has no effect.
I also tried to export (the same project) on my macbook pro, which is an Intel i9 with 16GB ram 512GB SSD... unfortunately the same poor result.. but that makes me more confident it's related to me, not the technology.
I guess I must be doing something wrong. Any suggestion? The songs I use sound perfect before importing. They are .mp3 files (originally bought music)

[yur2die4]

Warping can really mess with the quality of audio clips if you’re not keeping in mind what it’s doing to the track.