Cubas Pro 9 Audio suddenly Slow/ lower pitch

I have just upgraded to Cubase 9 Pro. I recorded some live vocals and guitar and all was ok, then suddenly one track started playing at about 1/2 speed and1/2 the pitch. All the other tracks are still playing normally so this is not a sound card sample rate issue. I have done no processing except a compressor and an effect send to reverb. I cannot discover what has happened. Any ideas?

Having done some more checking I now find that all the audio clips on track one have changed in pitch & speed. If I copy and past a clip from track one to any other track it does not correct it. Conversley, if I copy a clip from a track that is correct pitch & speed and past it to track one it stays correct. So the change is clip based.

Check your sample rates,…

Read my post properly…

If you want to upload a project folder somewhere with one piece of audio that is at the wrong tempo/pitch I could take a look.

I did…

If I import the audio files from the audio folder in the Cubase song they are as recorded. So this problem is easy to fix, but I would still like to know what I have done to change all clips on a track without knowing it!

As I said…I’ll take a look if you upload it somewhere.

Thank you for the offer. I tried. but when I copy the Cubase 9 song the copied version is all ok!! Does this tell you anything?!