Light flashing at angles 4.25 help?

Strange light reflection in all objects - including UE4 objects like the default blue camera model. panning around it flashes and is quite bad and did not occur in 4.23 and 4.24 so something has changed out of my control. I’ve tried reinstalling the 4.25 engine but same bug. Asked 3 times in unreal slackers and no response.

Image below shows the problem and panning slightly it disappears.

New Shots…

Access is denied to your file. A lot of people are talking about this, something to do with specular / reflections. You don’t usually see it in game though, right?

Sorry - link is fixed.

Yes, editor and simulate game shows the bug

Yes, it’s the same thing. I have no idea what’s causing it I’m afraid. I only get it badly in editor…

Static or dynamic lighting?

Seems both, and even if i delete all light sources the problem remains. “extra SS’s”