Cannot backup drive mounted as Windows junction

[combolek]

This is on Windows 11 Pro 23H2.
I have a main drive C: and a second drive mounted as junction C:\data2:

[C:\]dir

 Volume in drive C is WIN11          Serial number is 6a46:1ccf
 Directory of  C:\*
...
2024-04-12  02:27    <JUNCTION>    data2 [Volume{e2bafdae-1857-4d1a-98b4-31b88549e6f4}\]
...

Backup up of C: works as expected but backing up the second drive gives this error:

[C:\]kopia snapshot create c:\data2
Snapshotting root@tiger:c:\data2 ...
ERROR encountered 2 errors:
failed to prepare source: unable to get local filesystem entry: resolveSymlink: EvalSymlinks: too many links
upload error: unsupported source: root@tiger:c:\data2

I thought that maybe junctions are not supported yet, but note that I am not asking it to cross the junction boundary (i.e. follow it as symlink). I am just trying to backup the whole separate drive.
In any case, if this is an unsupported feature then please consider this issue as an enhancement request 😃
Thanks!