Hi vinaybaliyan,
Thank you for reaching Microsoft Community. Apologies for the inconvenience this has caused you.
May I know if this occurs when either the device is plugged in or running on battery while playing Fortnite?
While playing, is it only Fortnite that is running or there are also other applications running in the background?
Where did you download Fortnite from?
Please run these steps first on your Surface Laptop Studio then see if the issue persist:
1: Run Surface Diagnostic Toolkit
See: Fix common Surface problems using the Surface Diagnostic Toolkit (microsoft.com)
2: Check for Windows Update
Go to Windows Settings > Update & Security and select Check for updates
Make sure all updates need are installed including Optional updates
3: Update drivers and firmware
Check what is the current OS Build of your Windows version by going to Settings > System > About.
Go to Download driver and firmware for Surface, choose Surface Laptop
Then click the link next to Surface Laptop Studio then click Download on the next page.
Choose the .msi file that matches your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
4: Run System File Checker Tool
See: Using System File Checker in Windows (microsoft.com)
Kind regards,
Marrion