I am getting that same issue but on both sides. And mine almost seems as if it goes into part ambient mode at the same time too, because I hear more outside noise than with ANC off. I checked and there's no available update and fit test says they're good.
I don't know what you mean when you say "electric noise", but I hear a popping noise in my left bud when noise cancelling is on. It's extremely annoying, and I never had this issue with my Buds2 Pros.
