cpio worngly excluding some source directories.

I am trying copy backuppc pool to external directory.
/backuppc directory has following directories: cpool, pc, pool(empty)and trash (empty)

I am using this command from inside /backuppc directory

find . -mount -print | cpio -pdm <destination>

pc and pool directories are copied while "cpool" directory is not copied. (trash is also not copied but its not an issue)

cpool has millions of files which are hard links to files in pc directory

This used to work fine for past many months (backup scheduled weekly) but suddenly showing this strange behaviour.
On other backuppc server it is working fine.

I have checked "find . -mount -print > file_list" and cpool and its directories are correctly written to file_list

Please help troubleshooting

I have redirected output and std error to file and it has no mention of "cpool"

Thanks