Plsfixmypc21, please list full specs (ALL components), including the mfg. , model, & age of your current power supply, and those of the one that you just ordered. How long have you owned this PC, and how long ago did this problem start? Did you make any changes in your hardware around the time that the problem started? What application did you use to stress test your CPU and what was the maximum CPU temperature recorded during the test, and at idle? Please take two photos: (1) Picture of the PSU's label on it's side, showing the voltage table, and (2) Picture of the entire inside of your build. That picture should span from the front case fans to the rear fan, and all components in-between. Then upload those two photos to imgur and share the link here please. Also, in your listing of specs, please include the brand and model of your graphics card, and mention if you used a vertical GPU mount riser cable or any 3rd party PSU cables or adapters.
Addendum: And in answer to your direct question: Yes, it could very possibly be your PSU. I had a EVGA P2 850 reboot from simply updating Fortnite in the Epic launcher, and the issue was repeatable; I wasn't even gaming. The rig only had to power a Ryzen 5 2600 / GTX 1660 Ti, and yet it was reboot with a Super Flower OEM / platinum efficiency / 850 watt PSU. A new replacement under the 12 year warranty, absolutely resolved the issue. I look forward to your response, and I'm sorry that you're currently going through this. Sounds stressful.