Supermicro H11DSi Motherboard Instability Issues

I recently purchased a used Supermicro H11DSi Dual Epyc CPU motherboard from Ebay (China) and have been experiencing multiple strange freezes, post issues and overall instability from day one.  Makes me want to look at a different dual Epyc CPU motherboard vendor, but not many are out there that I have found.  I have been in the IT space for more years than I would like to admit, but never worked with real server hardware before.  Let me break down the setup, the issues, and what I have tried to resolve the issue.  

I’m open to what others may have experienced or have found solutions able to solve the issue below; if possible.  Because the issues are so inconsistent, I’m at a loss for what to do next.  When the device posts successfully, it detects the right CPUs, memory, etc.  Yet, I would think server hardware would be stable as a rock once operational.  Maybe I got sold a bad Motherboard, just not sure how to tell.

The Setup:

• 1 x Supermicro H11DSi v2 latest BIOS v3.0 (2024)
• 2 x AMD Eypc 7452 CPUs
• 2 x Epyc VRU (4U) Heat sync and Fans
• 16 x 32 DDR4 2666 ECC Server Memory (Micron) for a total of 512gb
• 1 x Corsair 850w Power supply (the server when under load seems to pull just over 400watts)
• 1 x WesternDigital 4tb Server HD

The Issues:

• Inconsistent posting issues at CPU Initialization, OPROM Initialization, and such.
• When I can get a post, the system loads Ubuntu 24 but runs and then freezes at various times
• Just never know what I will get every time I turn on the computer
• When it freezes (during post or in the OS) I cannot even hard power down, I need to turn off the PSU
• If I run Memtest86+ (from the Ubuntu boot) it always freezes at the same location no matter the amount of ram (32gb-512g)  Very odd as I would assume different results if a memory issue.

What I tried:

• Upgrading the BIOS from v2.1 (2020) to v3.0 (2024)
• Reset the BIOS by removing the battery and bridging the reset pads
• Select "Optimized BIOS setting” to see if this made any difference, none.
• Configured IPMI to monitor any watchdogs, etc (The old owner’s password needed to be changed)
• Removed all but one memory stick and changed it out, still same issue  Tried different configurations
• Loosed and tried Removing the VRUs to see if I got different results
• Disconnect all peripherals to see if this impacted anything (no change)
• I have not yet tried to remove the CPUs as they came pre-installed and I do not have the tool.

Before I think about scrapping the lemon, I wanted to make sure I was not missing something that might be more specific to this motherboard, CPUs, etc.  

Thanks.