Veah

Maybe this can clear up what unRAID is.

I don't believe the Realtek 8127 is ready for Unraid yet. Here's a copy/paste from AI slop:

Realtek RTL8127 support in Unraid is currently limited and depends on the Unraid version and available plugins.
As of Unraid 7.3, support for the Realtek RTL8127 is expected to be included natively via the kernel, eliminating the need for third-party plugins.
Until then, users are advised to check the Community Apps section for a Realtek driver plugin. The existing plugin for R8125/R8126/R8168/R8152/R8156 supports similar Realtek chips, and may offer compatibility or a workaround for the RTL8127.

Do you by chance have the old Mac address associated with your IP on the router?

This but you do not need to copy anything. When you install new drive, a parity build will start. Suggest you add the 20tb to array and put 24tb parity in it's place in same step so you only get hit with 1 parity build.

I'm a Seagate guy, Exos more specifically. Beyond Itimpi's example of a problem batch, I see no reason to vary the drive manufacturers or models.

I did not experience the amd c-state issue on a trx4 3960 cpu. Have a look here to see what's what.

That's how mine is connected

Maybe a manual controller
https://a.co/d/1fJdVM4
Edit:. Adding this clever one
https://a.co/d/fpA9gWs

Tools > System Devices
Checking a box and hitting the bind button is where you pass through devices that you could use for VMs.  It requires a restart to make active.
Mine looks like the attached where the 3 checked nics do not show up under my network settings, only the greyed out one does.

If remembering right go to br1 and uncheck it.  (This may work for bond too). Sort of like releasing it for use.  Then see if it's available to add to br0.

Suggest posting this here.  

My thoughts exactly.
 
Grab the RTL8126 PCI Drivers plugin from CA.

Have you tried to disable docker?  If it goes back to normal, it's one of your containers.

Working down.
-Dual nvme is great.  I use btrfs but I've read folks use zfs as well.  I believe it's slower but offers lots of other options that I am not best suited to speak on.
-You could put appdata and have usenet unpacking on the same drive.  That's what I do.  Sounds like you have another ssd you want to use anyway so either way seems valid.
-I think you got your mover going backwards on the Downloads share; don't know if that's part of your loading problem.  The images here are my Media and Download share settings.  My nvme_top is a btrfs mirror and the array is all 18TB spinners with 1 parity.  I think you can get to where you want if you try and copy those settings.  Use the Download for both your Downloads and Unpacking drives.

-If you are the only user, security probably won't be an issue provided you don't mess with things you don't know about.  Just be sure you are not using default passwords on your home router.
-Looks like a good build.  Might not even need to install the quadro, I'm not sure how well that igpu transcodes.  Could save a bit on power if you don't need to put it in there.  Same with the lsi card.  If you have enough sata available on MB, you can leave it out too.
-Parity drive, it needs to be equal or larger than the rest.  16 and 18 have been good cost/TB for a while.  The 20s may be getting there next.  I shop in this area for now.  It mostly depends how much money you want to spend.  FOR PERFORMANCE... Go with CMR drives!  Do not do SMR.
-If course play around with left over drives as desired.  Even smaller capacity ssd can host VMs which could be something to play with later on down the road.

Create your VM template and point the 'Primary vDisk Location' to the existing image you used before.  

That's certainly a good idea.  Let mover take care of it's thing when nothing is going on.

Looking again at pic, You got no parity... Is there data on drive 2?  If not, just do a new config.  

Nothing spinning sounds like no power.  Even without data cable they should spin up

Yes.  Format it for any use you want.

Looked up ROG STRIX B550-A GAMING and I only see x16 and x1 slots, no x4 This.  also of note, the bottom x16 slot is pcie gen 3 at 4 lanes.  You are looking only for an x1 GPU, the x4 option you mentioned will not work unless you mod an X1 slot to take the back out.  Not hard but will cards will only work at x1 speeds.
With that said, you want a gen3 x1 slot GPU.  
I saw some gt210 on eBay.  Could probably find an old quadro or firepro too.
 

You need to mark the parity disks so you can assign them correctly.  The rest of the array will sort itself out on a new config.

https://forums.unraid.net/topic/154463-announcing-new-unraid-os-license-keys/

Recommend having a good read here then copy/paste that last post.

Looks like Bridging is off.  Turn that on under network settings.  Suggest also disable Bonding unless you have a specific reason to use it.

Don't rule out bios settings too quick, there have been gremlins like this before.  Check bios is current.  Then try checking these:
Disable secure boot
Disable TPM 2.0
Disable CSM
Disable everything on the MB that you do not absolutely need.
 
If that does not help it boot unraid, shutdown and open the monster up and give it a good up and down.  Reseat all the cards and reconnect all the cables.  Consider dropping down to a single memory stick in the event one of those is errored.  
 
If still no, then removing cards one at a time.  
 
Hopefully at some point unraid starts up before there's nothing left you can remove.