Can't connect to DC from workstation using File Explorer

Here's a small piece of my topology:

SERVER2   - ePDC           (SERVER 2016 Essentials)
SERVER3   - Peer DC        (SERVER 2022 Standard)
RECEPTION - Workstation    (Windows 10 21H2)

SERVER2 is down for a week, waiting on a part from Dell. In the meantime I'm on RECEPTION trying to browse to a share on SERVER3 so I can copy over some large files (USB2 only on that machine, so there's no hope of anything fast with that).

I'm getting this error on RECEPTION:

Windows cannot access \\SERVER3\Files
0x80070035
The network path was not found

or

Windows cannot access \\SERVER3\Files
0x00004005
Unspecified error

Things I've tried:

1. Turned off the firewall on SERVER3
2. Enabled SMB in Windows Features
3. Enabled Network Sharing/File Discovery on both SERVER3 and RECEPTION
4. Enabled and started all services mentioned here

I can ping SERVER3 from RECEPTION without any problem. This also occurs from other workstations in the LAN. For some reason I'm unable to get to SERVER3 via File Explorer.

What further do I need to do so that I can connect to SERVER3?

---- EDIT 2022-09-29 ----

I was able to bring SERVER2 (the PDCe) back online—the Dell parts are still on order, but it's in a VM and I was able to move it over to a temporary host—and suddenly the connectivity problem from the workstations to the DC peer SERVER3 abated.

I have no idea why this happened.