Issue:
Last two updates, on restart, WAN has IPv6 address but no IPv4 address
Further:
The solve is easy, I just go to WAN interface and hit 'Save' at the bottom, it applies, and then I have an IPv4 address on WAN followed by a little later the IPv6 address shows up again on WAN. LAN interfaces have their IPv6 (and IPv4) details, but the missing IPv4 on WAN is initially keeping a few things from working after the update.
I will be able to do more testing later as far as the reboot w/out an update, but I do not have that change management window right now.