Ethernet connection to Mesa 7i76e disconnecting on its own after one minute

I just ordered two Mesa 7I76EUs, two Mesa THCAD2s, two Hp elitedesk 800 G1 USDT with i5 2.9ghz 16gb ram 512gb ssd, and two cat 8 ethernet cables. So I really want to keep trying until I have a working system. This is my third attempt at trying to achieve a working plasma table and so far I have only got to use my machine for five minutes at a time at most. I really appreciate the amazing support from you all

I connected a second PC to test wether the PC or the mesa board is dropping the connection. The result is the second PC works well for well over 20 minutes without interruptions or errors. it seems as the disconnected link was caused by the original PC. 

So does that mean you are in business and have a PC for spare parts? Hope so!
If not, I might be able to work in another site visit but it would cost you some footage for a YouTube video... 
There is an email that gets me on my @MrRodW YouTube channel

I should note that I have a HP EliteDesk 800 G1 that could never run Ethernet cards reliably
 for more than an hour or so UNTIL I upgraded the kernel to 7.x

It also requires:

disabling irq coalescing
isolcpus=3
and pinning the Ethernet IRQ to CPU 3

With these changes, I never get dropped packets even after months of uptime
with a PC used for compiling, youtube etc etc

I found the solution to my problem now all my computers work with no interruptions for at least 20 minutes. 
All I had to do was switch this setting from automatic to manual in the network settings and boom works now!

RMJ fabrication wrote:

All I had to do was switch this setting from automatic to manual in the network settings and boom works now!

If you used this:
forum.linuxcnc.org/27-driver-boards/3559...ethernet-mesa-boards
It clearly states to change that to manual.