Anyone experienced SW RAID1 preseed not creating partitions on 2nd HD?

I'm trying to create a 16.04.1 LTS x64 unattended preseed that creates a SW RAID1 across 2 drives and while testing it in a VM (VMware Player) the multiraid stanza doesn't create the partitions I ask on the 2nd hd (sdb) even if I specify sdb first. It creates them fine on sda. If I manually create the partitions on sdb, the preseed works. What am I doing wrong? The recipe is basically what many others have shared on the net. I'm only using SW RAID1 and no LVM. Does anything need to be done in the ks.cfg file? I haven't touched that. The configuration basically mirrors what I do when I configure SW RAID1 using Ubuntu's installer, which is the same as the how-tos on Youtube, etc.Thanksd-i partman-lvm/device_remove_lvm boolean true d-i partman-md/device_remove_md boolean true d-i partman-auto/method string raid d-i partman-auto/disk string /dev/sdb /dev/sda d-i partman-auto/expert_recipe string \ multiraid :: \ 5000 1000 5000 linux-swap \ $primary{ } method{ swap } . \ 70000 2000 70000 raid \ $primary{ } $bootable{ } method{ raid } . d-i partman-auto-raid/recipe string \ 1 2 0 ext4 / \ /dev/sdb2#/dev/sda2 . d-i partman-md/confirm boolean true d-i partman-md/confirm_nooverwrite boolean true d-i partman-partitioning/confirm_write_new_label boolean true d-i partman/choose_partition select finish d-i partman/confirm boolean true d-i partman/confirm_nooverwrite boolean true d-i mdadm/boot_degraded boolean true via /r/Ubuntu https://ift.tt/2IVFOeh