Laptop shuts down randomly when connected to power supply.

Hello, my Dell G3 3500, which is 3 years old, shuts down most of the time after sometime when connected to power supply. This has only occurred after I reinstall Windows 11 in June this year. The fans kick in, and then the taskbar shows an application with no icon, the error sound of Windows 11 triggers and then the laptop shuts down. Event Viewer cannot identify the problem and the surface of the laptop wasn't too hot as I have a cooling pad. It happens anytime, whether I browse Google or play some video games. Defender doesn't detect any virus but Microsoft is becoming a virus to me! SFC detects nothing and drivers are all good. All I know is that this problem never occurs again after turning on the laptop when it abruptly shut down. This problem might occur after 15 minutes or upto 3 hours. Please help me fix this as I always need to remain connected. Any solution would be very helpful! Thank you.