I’ve uploaded a studiorecording but when I was going to add an extra guitar track I noticed the pitch had changed a semitone and the tempo was a bit faster, what might have happened and how do I get it right?

It sounds like the sampling rate has changed from 44.1Kh to 48.000Kh. This would result in a pitching up of roughly a semitone and a few BPM faster.

Probably it’s a matter of matching your Project > Project Setup info to your intended samplerate and you may need to check your soundcard settings.