Automatic Rules not ceated by Setting up static WAN IP

[ole]

Hello,

as the subjects says, I did run into the bug?/problem. On a fresh installed opnsense v20.1 on APU4 the setup justified all fine for WAN as DHCP client. I'm behind a cable Modem (yes, not in bridge for some reasons) on the DMZ port of them. Hence a static WAN IP was intended to be used.
Anyway, I set up the static IP for interface WAN and "recreated" the WAN gateway (simply rename doesn't work). The common firewall rules where created, but still no access to Internet. After investigating, I had to manually create the outbound NAT rule:

even the automatic rule generation was active. So, is it bug, feature, or did I unintentionally forgot something?