Found a problem with WANs showing a "Pending" status under Gateways when running pfSense version 23.09.1-RELEASE. Documented and I filed to bug report this week.
This appears to be caused by the process dpinger. Tied to using a DHCP from the ISP. Does not happen if ISP is using a static IP for the WAN.
Occurs if the cable (RJ-45) between the modem and router/firewall is unplugged/replugged or if the modem is power reset. The problem happens with a single WAN and is not related to using a failover configuration. Can stay stuck in Pending state and is hard to get out of. Try, disabling the interface, then be sure the modem is fully online and ready to issue the IP by DHCP, and then reactive the interface. I've also tried releasing the IP and reassigning it under the Interfaces page.
If your ISP is Comcast, I also found a bug in their lease time for DHCPs if their default value is changed. The problem I found is when the lease time is changed, the modem will fail at 1/2 the assigned lease time. Logs will show monitoring pings don't respond. Way to fix this was to reissue another DHCP lease time or release the IP and reassign it under the Interfaces page
Another problem I found is modems in bridge mode will randomly disconnect because they stop responding to ARPs. Think the phSense default is 1200. Found it was necessary to reduce under 5 mins. I am using 240 for net.link.ether.inet.max_age found under Advanced/System Tunables. So far, this change appears to help stop the disconnects.