4K problem and U21 chip identification

After thermal grease replacement my xbox cant work in autodetect mode (So i cant play in 4k with HDR and freesync). I have replaced TDP158 but it doesn’t helped me. I think I found the reason because U21 chip is broken. Unfourtently I cant identify what is it and where I can buy it.
Could you please help me?
You can find pictured of the broken chip by url imgur. com/a/H92tunl

It’s an ESD Protection and Signal Booster for HDMI Source IC, made by STMicroelectronics, but you can’t buy it, because STMicroelectronics hasn’t released it to the public yet (there is no datasheet for it), so at this moment you can only get it from a donor board.


Did you manage to find it?

Hello … Good night. I also have the same problem and I can’t find the CI U21 anywhere. Unfortunately it is difficult to find defective devices to remove this component. I’m sorry for the English, I’m using Google translator. I will follow the topic

I have the same problem did you found where to buy it?

I just pulled U21 off a damaged board and took a shot of the bottom side of the IC with my microscope. I figured you all would find this interesting. This IC is quite complex. The small piece of solder on the bottom right of the image represents where the dot is on the chip on the top side.