VSTs out of tune - pitch changing when new midi pattern starts

Hi there ive just upraded to 9.5, have noticed now that when opening projects i was working on in 7.5, instances of xfer serum keep changing pitch by themselves, the pitch goes up a semitone, seems to be happening when the next midi pattern starts, also when i go in to edit the patch, as soon as i click a parameter the pitch goes up a semitone. Is this a cubase issue or a serum issue? havent noticed any other instruments doing it. both cubase and serum drivers are up to date