Motherboard model: TUF Gaming X570-Plus
UEFI Version: 2407
CPU:Ryzen 7 3700X
Memory kit part number (s) and amount in GB: Corsair CMW32GX4M2C3200C16 32GB
GPU: Gigabyte GeForce GTX 1050 4GB
SSD/HDDs/Optical drives: 500 GB Samsung 850 EVO, 1TB Samsung 860 EVO, no optical
PSU: Corsair HX850 850w
USB Devices (model/version number): Microsoft Keyboard, Logitch Mouse (not relevant)
Monitor: 2x Dell 23" 1080p monitors

CPU Cooler: Wraith PRISM heatsink+fan
PC CASE: Fractal Design Focus G
Operating system: N/A (Will be Windows 10)

Drivers Installed (include version): N/A
Any third Party temp/voltage software installed: None
System Overclocked (provide details)? No


Issue

The PC boots every time, I can enter the BIOS no problem. Without an SSD connected, I can load Live/Pre-installation versions of Ubuntu and Windows from USB flash drives without issue; I have run diagnostic tests (Memtest, CPU stress tests, SMART diagnostics) this way. The machine will also enter Windows setup and I can make it all the way to the screen in which you choose the drive to install windows (can't get further w/o a hard drive connected though).

The PC reboots, however, if a HDD or SSD is connected. If the 1TB Samsung 860 EVO is attached, the machine will reboot immediately after the POST screen. If the 500GB Samsung 850 EVO is attached, the machine will make it to the Windows setup loading screen and then immediately reboots. If I attach both the 1TB and 500GB SSDs, the machine reboots immediately after the POST screen. If the 500GB 850 EVO is attached by itself, I can boot to USB flash drives and load Live/Pre-install OSes. If I try to format or run a surface scan of the SSD, the machine immediately reboots. I get the same behavior if I hot plug either SSD after booting into a Live/Pre-install environment. I am completely baffled by the wildly different behavior of the system depending on which SSD is connected - doesn't make any sense to me. That fact led me down a rabbit hole into UEFI secure boot, but nothing I've done has worked so far.

I have tested both SSDs in another working PC and they work fine - I can format them, install stuff to them, no problems - the SSDs are otherwise in working order. I have already RMA'd the RAM and CPU - changing these had no effect on the problem. Removing a stick of RAM or changing RAM slots has no effect on the problem. So far, adjusting secure boot options has had no effect on the problem.

I am thinking I will have to RMA the motherboard but I want to exhaust my options first.