Under Preforming GPU

[_Fabled]

I would normally get 200+ FPS on my build playing Rainbow 6: Siege

R5 2600

2060S MSI

Aorus B450 Elite

Corsair Vengeance LPX 2x8 (3000MHz)

Corsair RM 750X

WD Blue 1TB

Kingston 240Gb (OS)

Once apon a time, I got the normal frames, then I noticed that I was running no more then 130 FPS Now, I've completely upgraded my rig

R7 2700x

2070S ROG STRIX

ROG STRIX B450-F Gaming

Corsair Vengeance RGB Pro 2x8 (3200MHz)

Same PSU and storage And I still get around 130FPS, but with a way beefier build. And according to MSI afterburner, my 2070S doesn't ever pass the 50C mark, so my GPU isn't running at max power I've tried: Replacing ALL parts Reinstalling Windows 10 Pro (3 times) Checked over NVIDIA control panel settings, set to default multiple times. Looked into MSI afterburner settings

[Neutraliz]

It could very well be just a bad game update.
And I mean, your GPU was a rather good upgrade, but your CPU isn't. It still the same architecture, and so, the same IPC and about the same single core performances. No real improvement was to be expected gaming-wize, for the CPU.
I would also suspect your CPU to be a bit of a hold back for your GPU. Not that bad, but it will certainly still there. 
Did you try to go into the NVIDIA pannel to switch power plan to maximum performances ?