I had the similar problem but didn't find any suitable solution. I only can give some workarounds:

Create unit files for each volume you want to mount. E.g.
```
[Unit]
Description=Start home

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/mount /dev/mapper/vg-home
ExecStop=/bin/umount /dev/mapper/vg-home

[Install]
WantedBy=local-fs.target
```

<br/>
Or add `x-systemd.device-timeout` option to your fstab mount rules. E.g.
```
UUID=d276a0d4-c95f-4792-a222-6d1451899de2 /home ext4 noatime,x-systemd.device-timeout=60s,errors=remount-ro 0 1
```
This will give systemd some time to do the work.<br/>
Official workaround from OpenSuse [Devices time out at boot time but appear later][2]
<br/>
<br/>
EDIT:
<br/>
<br/>
Also you can play around with:
```
[Install]
WantedBy=dev-mapper-vg\x2dhome.device
```
For trigger unit file.
<br/>
To get escaped path use [systemd-escape][3]

 [1]: https://unix.stackexchange.com/questions/404667/systemd-service-what-is-multi-user-target
 [2]: https://www.suse.com/support/kb/doc/?id=7018491
 [3]: https://www.freedesktop.org/software/systemd/man/systemd-escape.html