@julien-f that fixed it, thanks very much for the prompt resolution!

I'm running XO from source, just updated to the latest commit: b1e87

I've configured backup jobs to run XO config backups with and without pool metadata. The behaviour is the same in either case.
The backups run successfully, but restores fail. An example log of the restore fail below:

metadataBackup.restore
{
  "id": "3f885501-70f9-4219-8707-2a6515b0814e/xo-config-backups/9a515773-8912-4677-9e37-9e187341ecb9/20240101T164640Z",
  "pool": "5041a9f1-7687-65a8-04a3-67babe40e24d"
}
{
  "errno": -2,
  "code": "ENOENT",
  "syscall": "open",
  "path": "/run/xo-server/mounts/3f885501-70f9-4219-8707-2a6515b0814e/opt/xo/xo-builds/xen-orchestra-202401010940/packages/xo-server/xo-config-backups/9a515773-8912-4677-9e37-9e187341ecb9/20240101T164640Z/data.json",
  "message": "ENOENT: no such file or directory, open '/run/xo-server/mounts/3f885501-70f9-4219-8707-2a6515b0814e/opt/xo/xo-builds/xen-orchestra-202401010940/packages/xo-server/xo-config-backups/9a515773-8912-4677-9e37-9e187341ecb9/20240101T164640Z/data.json'",
  "name": "Error",
  "stack": "Error: ENOENT: no such file or directory, open '/run/xo-server/mounts/3f885501-70f9-4219-8707-2a6515b0814e/opt/xo/xo-builds/xen-orchestra-202401010940/packages/xo-server/xo-config-backups/9a515773-8912-4677-9e37-9e187341ecb9/20240101T164640Z/data.json'
From:
    at NfsHandler.addSyncStackTrace (/opt/xo/xo-builds/xen-orchestra-202401010940/@xen-orchestra/fs/src/local.js:18:26)
    at NfsHandler._readFile (/opt/xo/xo-builds/xen-orchestra-202401010940/@xen-orchestra/fs/src/local.js:176:41)
    at NfsHandler.apply [as __readFile] (/opt/xo/xo-builds/xen-orchestra-202401010940/@xen-orchestra/fs/src/abstract.js:284:29)
    at NfsHandler.readFile (/opt/xo/xo-builds/xen-orchestra-202401010940/node_modules/limit-concurrency-decorator/src/index.js:85:24)
    at RestoreMetadataBackup.run (file:///opt/xo/xo-builds/xen-orchestra-202401010940/@xen-orchestra/backups/RestoreMetadataBackup.mjs:25:34)"
}

I really don't have that path when I check the xo machine, but I have a similar one: /run/xo-server/mounts/3f885501-70f9-4219-8707-2a6515b0814e/xo-config-backups/9a515773-8912-4677-9e37-9e187341ecb9/20240101T164640Z

Any ideas what would be causing this? I considered filing an issue on GitHub, but I have no idea if anyone else can reproduce this behaviour so it seemed like I should start here.