XBOX Series X black screen above 1080p

So I’ve replaced the HDMI port and retimer and bypassed the ESD booster. If I go above 1080p, I get a black screen, and it still flickers. At 1080p, it works fine; at 720p, what’s the best next step to figure this out? Any help would be greatly appreciated

Update: I just installed the Ubermicros ESD alternative, and now I can get it to display at 1440p, but it’s artifacting badly at that resolution. I set it to 1080p and played Halo Infinite for about an hour with no issues. It’s got to be something simple I’m missing