New Domain Users load the black screen first-time setup extremely slowly, then if they open Built-In Administrator's User folder, all problems go away

I was planning to post this to r/techsupport, but they've gone dark for the time being.

I've got some VMs that I put onto a VMware host, and setup a Domain controller, followed a pretty basic guide. Got the other VMs to join the domain, setup only one basic GPO for NTP time source.

I'm kind of a newb at this, so please be patient and don't assume I know everything you know. It's Windows Server 2019 Standard edition. The Domain controller and all other VMs are as well.

I created these VMs from an .ova template from a company that we do a ton of our application development on, and I've tried their tech support already. Ultimately the problem lies not in their software, but with Windows, so they are not as heavily trained on that part. They're at a loss so far with the people I've talked to. I even dragged our IT into it and their first suggestion was to get them all fully updated because a patch roll-up might have fixed it.

The primary issue was actually happening before any of that, but appears to only be an issue for new users that are domain users. (I also need to test if it happens to local user accounts). When a new domain user connects to a VM that they haven't connected to before, the first time setup runs with a black fullscreen, that little white box in the top left side runs different pieces of the "applying first-time settings". It seems to often hang on web customization profile or something like that. (I'll try to add screenshots later) Eventually after at least 10-15 minutes of that, the user will be logged in and sitting on desktop. This doesn't end the problem however. You cannot open Control panel, CMD, settings, use the built in windows search bar to type more than one character, basically ALL programs are stuck if you try to open them. Some of them DO open eventually but do this every single time and again takes at least 10 to 15 minutes.

I've found a workaround purely by happenstance, and it is that if I click to go into file explorer, and try to open C:\\Users\\Administrator (prompt for admin password for standard users and other admins) then suddenly all is right with the world all at once. Every program you previously tried to open now suddenly opens and every single thing you tried to run, runs. It's like there's some underlying permissions that are broken for new users, and those permissions are buried in gaining access to that folder, just ONCE.

I've run Windows Update, and made absolutely sure they're all fully updated (as far as Windows Update thinks they are at least). I tell it to check again and finds nothing. So no fixes or patches that would have fixed this have been downloaded from that as far as I know. That didn't fix it as you may have guessed. I've tried disabling UAC, doesn't matter. Happens to domain admins and domain users so far. Just doesn't happen to built-in Administrator. If it adds anything, Administrator is the only local account on the VM when I make them join the domain. When I created the new VM, I go through first-time setup, make the local admin password, and then immediately set an IP address and join the domain.

If any of you have seen this before, I'm all ears, this is driving me crazy.

My googling skills are failing, because I'm finding NOTHING like this and tons of BS that has nothing to do with this issue.