2018 F150 5.0 Cylinder 4 Misfire

Long story short, I've been trying to diagnose a cylinder 4 misfire on a customer's 2018 F150 5.0. I've gone through all of the usual suspects, swapping around plugs, coils, and port injectors (leaving only the direct injectors, which I suspect to be the problem at this point), intake runner control flaps (super common failure on 5.0s, etc.. Checked compression, it's excellent. Relative compression test in the scan tool looks perfect as well.
I was initially getting misfires on all of bank 1, but I unplugged the upstream O2S on bank 1, and now looking at the power balance on the scan tool, cylinder 4 is certainly the culprit. I then logged the cylinder 1 and 4 coils on my oscilloscope, and the graphs looked nearly identical. I had also previously checked for spark with a spark tester, and it looked very good and consistent on cylinder 4, so I don't think spark is an issue here.

The only thing I can find that looks out of sorts is the fuel pressure. It's a bit higher than the commanded pressure. What I'm thinking is that maybe the direct injector is sticking open a little bit? It usually starts misfiring at idle after revving, so maybe the DI sticks open even after it switches back to PFI?
As I said, I've already done a compression test, so I don't believe there are any issues with the valves or anything mechanical.Spark is good, and I already swapped around the port injectors. So at this point, it's really looking like it's down to the direct injector.
I'm gaining confidence in this theory the more I think about it, let me know what you all think. I'd tear into it and swap it to another cylinder to check it, but I'll have to run it by the customer first before I do way more work that I'm already probably undercharging for.

I don't recall if the 5.0's have this option? But have a look in your scan tool for a 'FUEL_MASS_DI' test. It's a bidirectional function that will allow you to command the PCM to use either the port or direct injectors only, instead of the PCM swapping between them at will (or blending between the two).

If you can make the misfire go away by switching back and forth between port and direct injectors, you may be onto something.

They do, I tried that before and I don't think it made any difference. This was before I undid the O2S though, so I'll try again to confirm.
It sucks though, I'm at a loss as to what else could possibly be causing this. I'm running out of cylinder-specific parts lol.

I'm happy to report that the truck is now running great! 8 new Motorcraft direct injectors is all it took... fortunately the owner opted to replace all 8 rather than just the one to hopefully avoid this in the future.
As far as diagnosing it, after running the truck, I had pulled the cylinder 4 plug out and stuck my borescope in there. Sure enough, the injector was dripping fuel, and within a minute or so, it was pooling on the top of the piston. That'll certainly cause a rich misfire. Test drove it, idled it, revved it, and it's silky smooth now.

Good work, thank you for posting the fix