Audio mix down coming out SLOWER then recording formant

i have the studio live 32.4.2 and cubase 8 pro, using iMac, i tried to contact steinburg through phone, but unavailable.
my issue is,
i have recorded a band and everything came out fine on the cubase software on my iMac, i mixed it and was ready to Export/Audio mix down. i selected mP3 for export,(note:i tried all the options for audio mix down)… and when i listen to the mix down on my iTunes or computer, it plays slower then the actually recording. so thats my issue, and I’m having trouble figuring this one out. i have used cubase le before. and I’m familiar with cubase, so this is my first issue as a long time cubase user. i need this figured out asap. so i can start recording once again.

The samplerate does not match.
Make sure the project is set to the same as the audio interface and Export format.