I observed similar behavior, although not recently. I can confirm that it is wireless related.
I’m on KDE and I noticed the flickering was almost always when I had the wireless-status-icon menu open. I think what happens when I open the menu is that it scans for available networks. So I attributed it to that.
However, as I didn’t have it recently, I’m wondering if it depends on the precise access point. I have 3 AP, but stick to one most of the time. Or, maybe the “good” one is (not) on 5 GHz. I’ll have to check that.