Really odd. The dull menu is a symptom of the Zidoo outputting an HDR image (either HDR10 or DV) but the TV not recognising that and processing it as SDR. The black screen and image in the corner? Goodness knows!!! What makes you think it's switching EDIDs? I don't think so - If it was doing that, it wouldn't change resolution, it would remain at the current resolution/refresh but switch HDR back to Auto. I think there's something else at play here... I'll try and replicate by taking my Vertex out the loop and set a custom uploaded EDID in the Zidoo.