The top is Safari, the bottom is Edge. I just happened upon this because Safari youtube 4k was lagging like crazy so decided to see if the same happened on edge and it didn't stutter once. But I then noticed how much dimmer the video was as well as the colors not looking as vibrant. Both videos are in 4K HDR though. I've restarted both browsers and disabled the extensions I had on just in case, didn't seem to change anything except for how safari looked brightness-wise. Brightness is maxed on both videos. Have I missed some other setting somewhere? Or is edge just not doing HDR right currently?