problem in shared screen

Hi. Everytime i enter a class with a host (a specific class) when he shares his screen my screen goes dark from time to time and then back to normal. I get at the beginning of the session a message "esmorecimento de imagem..." at the beginning of the session.

I'm recording the session with obs but that isn's a problem with other sessions of this user or in other computers/mobile. Only on this computer.