Server Backup fails with system writer not found , event 517, only when backing up System State

This has happened with Server 2016 DataCenter, Server 2019 DataCenter, and Server 2022 DataCenter. It happens with standalone servers and with the DC, which is the most problematic of the bunch.

If I run server backup and choose just a disk drive or drives, or even Hyper-V the backups work just fine. But if I include system state they fail. If I try to backup jonly system state, it fails. Normally I'd say fine, just backup the drives, but on the DC one really should backup the system state.

The backup fails and the error log says The backup operation that started at '‎2023‎-‎08‎-‎29T23:26:58.659546100Z' has failed with following error code '0x80780102' (The system writer is not found in the backup.).

1. The VSS service is running and I've tried restarting it.
   vssadmin list writers does not show anything called System Writer in any of the servers, even a freshly installed 2022 one (with the server backup role added).
2. I have tried reregistering VSS and making sure permissions are correct with
   Takeown /f %windir%\winsxs\temp\PendingRenames /a
   icacls %windir%\winsxs\temp\PendingRenames /grant "NT AUTHORITY\SYSTEM:(RX)"
   icacls %windir%\winsxs\temp\PendingRenames /grant "NT Service\trustedinstaller:(F)"
   icacls %windir%\winsxs\temp\PendingRenames /grant BUILTIN\Users:(RX)
   Takeown /f %windir%\winsxs\filemaps* /a
   icacls %windir%\winsxs\filemaps*.* /grant "NT AUTHORITY\SYSTEM:(RX)"
   icacls %windir%\winsxs\filemaps*.* /grant "NT Service\trustedinstaller:(F)"
   icacls %windir%\winsxs\filemaps*.* /grant BUILTIN\Users:(RX)
   net stop cryptsvc
   net start cryptsvc
3. I have verified in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VSS\VssAccessControl that the value of NT AUTHORITY\NETWORK SERVICE (REG_DWORD) is 1.
4. I have tried the workaround in https://video2.skills-academy.com/en-us/troubleshoot/windows-server/backup-and-storage/event-id-513-vss-windows-server?source=recommendations wherein one modifies the permissions of MSLLDP using sc sdset to att NT AUTHORITY\SERVICE
5. The backup volume is on a network file server, and it works fine when I'm only backing up disks (C:, D:, and System Reserved, for example).
6. I am a domain admin and I have run server backup both As Administrator and as a domain admin.
7. Except for the domain controller itself, these are freshly installed 2019 servers and 2022 servers added to the domain with Microsoft updates done before adding roles (including the server backup role).