Try downgrade you graphic driver, I personnaly noticed since somes updates VR and my pc in general don't work well like before, to do that you can go to this link: https://www.nvidia.fr/Download/Find.aspx?lang=fr (in french)
https://www.nvidia.fr/Download/Find.aspx?lang= (in english)
and choose the 536.99 and install it (you don't need DDU to clean the graphic driver)

I thought it was uselless because I can verify with Steam but no, you need to fully uninstall SteamVR and delete all files that remain the SteamVR folder, if you can't because it tell removeusbhelper.exe still running or any app, you can find in the task manager under details section and find the app to end the task after, you can delete the rest and reinstall SteamVR.

You lost only the play zone, the bindings files for your games can be found in C:\user\documents\steamvr\input

If you just install the new graphic driver without DDU, you don't lose your Nvidia GeForce Experience settings

But Nvidia shoud tell you to update your driver but personnaly, my pc run better now I think.

Hope this guide helped someone who was in the same situation than me.