>It's strange that your having problems with the private nic, is it loosing it's ip address? Assigned by dhcp?<
It was assigned STATIC. I found the problem this morning after Googling for a long time. It is an issue with the AlmaLinux 8.4 installer. When you are in the installer, and set up the network, and then forget to turn on one of the NICs before leaving, and then find out you cannot ping that NIC, and go back into Networking and turn it on and save it, you will be able to ping it fine. That is exactly what I did. Where it fails when you go in the second time is it does NOT change the ONBOOT setting from no to yes in the /etc/sysconfig/network-scripts/ifcfg-<nic>. Therefore, the next time you boot, and it reads those files, it sees it it set to no, so it doesn't activate the NIC. the command line tools to activate the NIC will work fine to activate it. The problem is none of them change ONBOOT setting in the file so the next time you boot, it will be no NIC again.
What threw me for so long is I've had things like this happen before with Windows. If it finds a loop, it shuts down a NIC. The way I traced it down to the OS install is in ESXi, I set snapshots along the way, so first I went back to the the Control Panel Installed snapshot, then OS Installed snapshot and I still had it. Then I found it online, so I rolled forward to my Configured snapshot so I didn't lose any work.