[Samba] vfs_shadow_copy2 not working

[douxevip]

So I'm trying to get shadow copies to work with Windows clients. The snapshots are being stored at /test/.zfs/snapshot

The snapshots are being named like so:

autosnap_2019-08-10_21:00:00_frequently
autosnap_2019-08-10_21:00:00_monthly
autosnap_2019-08-10_22:00:00_hourly

This is in my smb.conf:

[test]
vfs objects = shadow_copy2
shadow:snapdir = /test/.zfs/snapshot
shadow:snapprefix = ^autosnap_
shadow:format = %Y-%m-%d_%H:%M:%S_\(frequently\)\{0,1\}\(hourly\)\{0,1\}\(daily\)\{0,1\}\(monthly\)\{0,1\}
#shadow:delimiter = _
shadow:sort = desc
shadow:localtime = no

I've also tried it with the delimiter line uncommented (and then removing the underscore from the snapprefix), I've tried putting the shadow:format syntax between quotation marks ("") as well, but it doesn't just show up in Windows.

I think that syntax should just work according to the manual. Why is it not working?