Model: Legion Slim 5 R7 7840s 4060
Describe the issue: My Slim 5 has been performing really poorly in games. It all started when one of the tech support representatives asked me to reinstall Windows via USB to fix a Wi-Fi issue. Ever since then, I haven’t been able to play a single game.
Despite several complaints and checks, they always come back with the same response: "The device is working as per the design." However, my gaming performance has dropped significantly. For example:
EAFC: Previously 150+ FPS, now barely 60, with huge stuttering issues.
RDR2 - Previously 75+, now doesn't even reach 50.
GTA 5: Previously 140+ FPS at 1440p, now only 70 FPS.
Marvel Rivals: 120 FPS on low settings. (Game optimises it to Low settings)
Even low-end games like Rocket League experience FPS drops.
What have you tried already?: Updating/Reinstalling Drivers, DDU, BIOS update, Resetting windows, contact tech support.
When did it start producing the issue: After Windows reinstallation on October 28th, 2024
Did you install new drivers or software?: Yes
Can you provide images/videos to show us the issue: Yes, I've attach the link of my benchmarks along with gaming clips as well.
https://drive.google.com/drive/folders/1ZN9qba8liMe6aLwmLlyYEGfx3Q3RsHff?usp=sharing

