Small window image quality

[NAZAREPAIR]

Hello Guys.

I have a video capture on the corner of the screen, but is very pixelized.

I found a solution before i don´t remember what it was but i just licked somewere and the image kind of corrected himself like a suavization.

I am recording 4k and when i reduce the size to make just a small window on corner of the screen the image gets bad like you can tell the pixels.

Anybody know what setting is this that i am missing?

Thanks