Hello,
No I didn't change anything, I re-downloaded the last version of Cross and re-installed it.
I also remove the preference files of the software in:
~/Library/Preferences/com.mixvibes.Cross.plist
~/Library/Preferences/Mixvibes
The issue has disappeared, I hope it will last… I work for Apple so as the issue seems software I still have a few tips to try for next time

Thanks guys.