Open GL error on update photoshop 2020

Hey there !

I'm sorry to create this topic, as I could see several solutions were offered through other topics, but none did the trick for me. 

As said in the title, I've got the famous OpenGl bug and I can't rotate my canva since I updated to the last version of Photoshop (checkbox is grayed when going to settings/permormances/use graphic processor).

Fun fact : I forgot to erase the old version, wich was the Ps2017, and if I run this software, Open GL works perfectly ! that's sooo frustrating ! ^^ 

I of course checked for any update for my AMD Radeon HD 6900's driver.

I tried to set Open GL options in the AMD settings (the only thing I found that was looking as it was in gaming/3d application settings/frame rate control/OpenGL triple Buffering).

I checked if there was another graphic card detected, and there is not. 

I tried the trick of adding AllowOldGPUS command on regedit. 

I'm not comfy with what's said in the "info" window of Ps, but it seems that openGL parameters are activated, here is a copy of the concerned part : 

Dessin OpenGL : Activé.
Anciens GPU OpenGL autorisés : Non détectés.
Mode de dessin OpenGL : Avancé
Mode OpenGL normal autorisé : Vrai.
Mode OpenGL avancé autorisé : Vrai.

Also, it seems the graphic card is detected as well :

glgpu[0].GLName="AMD Radeon HD 6900 Series"

I'm running out of ideas, any help would be most welcome ! 

Thank you very much