How to fix swap file device timed out in LVM setup?

Fresh install of 20.04 boots normally, but I see this in syslog at every boot.

It looks like no swap file is being allocated. How can I fix this?

systemd-fsckd.service: Succeeded.
dev-mapper-vgubuntu\x2dswap_1.device: Job dev-mapper-**vgubuntu\x2dswap_1.device/start timed out**.
Timed out waiting for device /dev/mapper/vgubuntu-swap_1.
Dependency failed for /dev/mapper/vgubuntu-swap_1.
Dependency failed for Swap.
swap.target: Job swap.target/start failed with result 'dependency'.
dev-mapper-vgubuntu\x2dswap_1.swap: Job dev-mapper-vgubuntu\x2dswap_1.swap/start failed with result 'dependency'.
dev-mapper-vgubuntu\x2dswap_1.device: Job dev-mapper-vgubuntu\x2dswap_1.device/start failed with result 'timeout'.
May 14 13:41:08 localhost systemd[1]: Reached target System Initialization.

/etc/fstab contains:

/dev/mapper/vgubuntu-swap_1 none swap sw 0 0

The 2 logical volumes in vgubuntu (root & swap_1) are both allocated to PV /dev/mapper/pdc_biabhicfdd5, which is 2 SSDs configured in a (BIOS) RAID1 array.

/proc/swaps has no entries.

swapon -a returns error "cannot open /dev/mapper/vgubuntu-swap_1: No such file or directory".

sudo lvscan shows "/dev/vgubuntu/swap_1" as inactive.

So I activated /dev/vgubuntu/swap_1 with sudo lvchange, then sudo swapon -a succeeded, and vmstat now shows Swap space available.

But, when rebooted, everything reverts, and the same errors are in syslog.

So, it looks like the Swap logical volume is not being activated during boot for some reason.

Any ideas!