I ran windows update last night after a session of Cyberpunk 2077.
When i returned to the game this morning my performance was almost halved.
I tried a couple of things like updating GPU drivers and Clearing Shader Cache but to no avail.
I was not until i remembered the windows update i had ran last night,
I went into windows update history, removed the update from the night before (KB5055683) and restarted my machine.

And now it runs like it used to.

Anyway just a heads up for anyone experiencing sudden performance drops from boot to boot.