[SOLVED] hassio won't start on wifi unless eth0 is also up

I did an initial setup of HA on a RPi 3B using a hassio image with dhcp on eth0, then later decided to switch to wifi (because I need the wired connection for other purposes).
I managed to bring configure the wifi connection with a separate ip address (static on my router) but on reboot HA’s web interface won’t start if only wifi was active on boot (i.e. eth0’s cable is unplugged). ssh is also refusing connections on port 22 and the ‘host’ access (port 22222) hangs just before actual login (verbose output shows successful authentication but stops after environment variables have been sent).
Details of my setup are listed below:
HA 88.2 (hassio/RPi)
using self-signed certs with nginx
wifi ipv4 set to auto (dhcp servers static IP address)
eth0 ipv4 set to auto (although not needed)
I manually set autoconnect-priority higher for wifi to make sure its the first interface to go up.
Any ideas how to resolve this will be highly appreciated.

solved by explicitly setting never-default like this:
nmcli c mod eth0 ipv4.never-default true
nmcli c mod eth0 ipv6.never-default true
where eth0 should be the name/UUID of the wired connection