I see you got no reply. I do not know why initially the imported audio track would mickey mouse. I have never had that happen.
I searched and found that one can affect tempo and pitch by converting the imported audio clip to a groove clip, and then manipulate in loop view. I have never used this, and so you should research groove clips and loops before taking any action. I experimented by importing audio into an empty project, and was able to make changes, but I cannot seem to undo what I did...so be careful! I would suggest a test project to play with this.
With luck, someone will come up with the correct answer to your question - Why this happened in the first place. Good luck!
FWIW