Question PC restart when gaming

[Serben98]

Motherboard: MSI MPG B550 Gaming Plus Gaming Motherboard
CPU: RYZEN 7 3800x 3rd Gen
PSU: EVGA - 1000W ATX /EPS 80 Plus Gold Modular Power Supply - Black
GPU: GeForce RTX 2070 SUPER VENTUS GP OC
(sorry for the random font, Im copying directly from my orders.)

So, I had purchased a prebuilt iBUYPOWER PC and have upgraded it. It wasn't until recently, when I upgraded my CPU, PSU, and Motherboard that it began restarting when I open games. I can browse all day, talk on discord, but as soon as a game opens up the timer begins.
Upon startup, it will show the MSI screen, so it is a full restart.
I downloaded a monitor (NZXT CAM) and the CPU and GPU stay below 60 c. My CPU clocks at about 4220, but upon performing a stress test (MSI Afterburner) , I've ruled the CPU out as my issue.
I tried swapping out the power cable for my PC and it still persists. I believe the issue is in my Power Supply, but I wanted to ask for any help here before replacing a brand new component.
I've attempted the comments on the other forums, and I'm still lost.

 

[drivinfast247]

Did you reinstall Windows after the motherboard upgrade? If not, start with that.

 

[jonnyguru]

What PSU was in it before? Can you put it back in there to see if the reboots go away?

The FSP based EVGA G+ isn't necessarily an exceptional PSU.

 

[Serben98]

Did you reinstall Windows after the motherboard upgrade? If not, start with that.

yeah, It stayed on my SSD so upon installation I wiped it and started over.

 

[Serben98]

What PSU was in it before? Can you put it back in there to see if the reboots go away?

The FSP based EVGA G+ isn't necessarily an exceptional PSU.

I dont remember exactly what it was, buyt it was a 600w. I had sold my old parts to a friend from work since she was trying to build a PC. (Help out the homies, y'know)