Photoshop can't see my GPU

Guys, please, i need help.

I have a probleme (GPU isn't available), that doesn't fixed by any intsruction suffered by Adobe, connected with this probleme. I am iMac 5k user (late 2014) with newest operating system (mac OS Catalina, that i updated only to fix this probleme, but nothing to fix). Photoshop version 21.2, but even in previous version was this proble, which suddenly appeared, because everything was right. 

Finaly:

1. I updated operating system - nothing;

2. I deleted files, in Adobe Photoshop 2020 Settings, connected with photoshop preferences - nothing;

3. I even tried to delete sniffer.exe - nothing.

What else can i do to fix this probleme? Please, help me, because it is really a very big probleme for me.