GPU slown down after reintalling windows.

Specs:
Laptop Model: Precision 7740
Processor: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz 2.59 GHz
GPUs:
  -  Intel(R) UHD Graphics 630
  -  NVIDIA Quadro RTX 3000
System type: 64bit
RAM: 32GB
OS: Windows 10 Pro

Problem:
So I recently buy this laptop.
I was working very good. I decided to test it really fast so I installed Roblox and stated playing. On maximal settings it even in very chaotic moments had around 200 - 250 or sometimes even 300FPS. But because this laptop was used before so I want to be sure I will have clean install of Windows. I downloaded ISO from official website, record it on flashdrive using Rufus and installed. After it has finished it installed all drivers it self. Then I lunched the same game on Roblox it was getting in on low settings max 140FPS and then I turned maximum graphics like before and started playing more it dropped to 60 and even sometimes 40FPS. I was thinking maybe those drivers were incorrect, so I downloaded official drivers from dell site using service tag to make sure I have right one. And I started installing them in this order:
- BIOS
- Chipset
- Serial ATA
- Graphics cards
I was doing it without internet to don't get them installed automatically by MS Store. And for safety after every one of these files I was restarting my laptop. But in the end it didn't change anything. Now my question is why it happened? Should I first delete whole disk using some programs or something like that? Or is it some time of manufacture lock that can be removed using something? Is there like limiter how much app can use GPU resources? I already tried setting highest priority in task manager, changing windows energy plan to best performance and setting in NVIDIA driver to always take performance as priority.

Please help, I don't have any idea what to do now.