As stated in OP. Precisely same settings on both successive images. Very random in nature. I've only noted it in the VF and not in LV.Can occur with multiple lenses. So, it's not aperture, unless the camera is stopping it down for some reason. I...
I have this exact same issue. Except, I'm using the "kit" Canon 24-105 F4L mostly but, it also occurs on my other lenses... A new Tamron 35mm 1.4, Canon 70-200 F4L, Tokina 11-16, Canon 50mm 1.8 STM..... If it was a lens problem this would also oc...