Anyway, I've only seen it on my MkIV lights. Specifically, two that use the XHP35 HI emitter. I have another two MkIV models, but they use the XHP 50.2, and I haven't used them much outside in the cold, so I can't say whether or not they have the same issue. My older Zebras are fine in the cold.
My new SC700d does it intermittently but not enough to be an issue. Purchased Oct '19. It is not cold related in my case though. I use a Samsung 50E battery.