Hello
My first idea it can be a virus, but you told the white stripes comes quickly and not creeping. So i think its a temporal genetic mistake.
It can be these stripes stand the whole year, but more possible in my eyes is that the gone in a few weeks or months. The plant make a transition over the year, with difficult traps and petiole. So its more probably it goes away anytime.
Thats my opinion.
Bye Thomas