ZFS missing filesystem after interrupted backup

I have two filesystems in a pool, backup/nextcloud and backup/vm. Today, after a send/receive transfer was interrupted before it could finish (I was backing stuff up to these filesystems), I no longer see backup/vm, but the space it was taking up is still not freed up (and therefore I hope it can be easily brought back).

zfs list output:

NAME               USED  AVAIL     REFER  MOUNTPOINT
backup             613G  2.91T      104K  /backup
backup/nextcloud   613G  2.91T      607G  /backup/nextcloud

zpool status:

  pool: backup
 state: ONLINE
config:

    NAME                      STATE     READ WRITE CKSUM
    backup                    ONLINE       0     0     0
      wwn-0x5000c500c00fffbf  ONLINE       0     0     0
      wwn-0x5000c500c010b173  ONLINE       0     0     0

zfs history backup (relevant last few days):

2021-02-25.21:58:11 zfs create backup/vm
2021-02-25.22:50:52 zfs recv -Fu backup/vm
2021-02-26.12:01:13 zfs snapshot -r backup/nextcloud@20210226
2021-02-26.12:03:15 zfs recv -Fu backup/vm
2021-02-26.14:46:05 zfs send -RI backup/vm@20210221 backup/vm@20210226
2021-02-27.12:01:23 zfs snapshot -r backup/nextcloud@20210227
2021-02-27.12:04:04 zfs recv -Fu backup/vm
2021-02-28.12:29:55 zfs recv -Fu backup/vm
2021-02-28.14:11:35 zfs send -RI backup/vm@20210226 backup/vm@20210228
2021-02-28.14:12:38 zfs snapshot -r backup/nextcloud@20210228
2021-02-28.16:41:44 zfs send -RI backup/nextcloud@20210221 backup/nextcloud@20210228
2021-03-01.12:00:19 zfs snapshot -r backup/nextcloud@20210301
2021-03-01.15:56:15 zpool import -c /etc/zfs/zpool.cache -aN
2021-03-01.18:05:58 zpool import -c /etc/zfs/zpool.cache -aN

I've tried rebooting, reimporting, and everything similar sanity passes, but to no avail.

Edit: added zfs history backup output

What could be done to bring back the filesystem? (zfs version 2.0.3_5.11.1.arch1.1-1)