extremely frequent random reboots; cannot isolate the issue

Hi everyone. I hate to bother folks with my problem, but I've been experiencing unexpected Windows reboots for almost a month now and just can't figure out what the problem is. I'm really hoping some kind soul will help me out.

Problem: My PC will (seemingly) randomly reboot at different times. In some instances, it will reboot seconds or minutes after the previous reboot. Other times it might be hours. I never get a BSOD, just a full reboot back into the log-in screen. This behavior started after I installed Valorant video game for my son. I have no idea if it's related (and the game is now uninstalled) but that's the only thing that I can think of that changed around the time the problems started.

Attempted Fixes: Here is a partial list of things I've tried to fix it:
- run memtest86 - no errors found
- run chkdsk - no errors or problems found
- remove heatsync, apply thermal paste, reinstall
- remove and reinstall all RAM
- disconnect all peripherals except for mouse and keyboard
- turn off automatic reboot
- windows startup repair (this does not work)
- reinstalled windows over existing build
- monitor temperatures in real time (never rise over 35-30 C or so)
- download and install updated drivers for motherboard, chipset, LAN, etc from the Asus website

Notes: There are a TON of NOT LOADED items in my ntbtlog file specific to @CPU.inf,%intelppm.devicedesc%;Intel Processor

Windows 10 Home (Version 1909 - OS Build 18363.836)

Any help would be greatly appreciated. I have no yet tried a full reinstall of Windows, but I'm really trying to avoid that if at all possible. I have a decent amount of apps/programs that I'd prefer to not have to reinstall and configure.

*Edited* - I am now only able to enter Windows via Safe Mode

Thanks!