Random Layer lines appear in vase mode

Guys what should I possibly look into, this print is ment to be a vase mode print but occasionally there would be these layer shifts for a single layer and then it resumes normally.This effect is not there is back right corner and it is present every where else

Printer Vcore 3.1
500x500x500
speeds 35mm/s
layer thickness 0.4mm

Any help would be great!
TIA