It's definitely firmware related (02.05.02). I've been writing software that takes measurements from the scope, and the faster I poll it, the more flickering that happens. But perhaps The1 (and others) can test the software and see if it produces (any or more) flickering for them as well; I'll upload it a little later and make a note here.
Also, I discovered (although perhaps someone has found this out earlier) why they don't mention reading the Phase measurements from the scope in the programming manual - even though they list all of the other 20 possible measurements. That's because there's another screen redraw bug when you read the Phase, which causes the scope to write the Phase measurements to oddball parts of the LCD - and those errant writes will remain in the areas of the screen which aren't refreshed (the border all around) until you either swap skins or reboot. I actually think the two bugs are related - at least it seems like it might be when you run the software,
In any case, it's pretty damn annoying. I just bought my scope through a normal dealer here in Europe (with a 30 day free trial), so I'm planning to return it (and keep returning it) until they fix the bug. Of course, if more customers did that (which I guess isn't likely, given cheap Chinese suppliers), they would have to address the issue. I just wonder what they're going to do in my case - downgrade me to 02.04.02?
Edit: Uploaded my control software here:
https://www.eevblog.com/forum/index.php?topic=4174.0 - Anyone suffering from the flickering (and even those who aren't) might test this to see if it exacerbates the problem.
Edit: Attached screen capture showing redraw bug of Phase measurement.