Gateway

[tong2x]

may 5G gateway disconnects alot, which may require it to reboot.
may issue is that if the modem is rebooted somehow the monitor IP, gets marked as down. what I do is replace it with another IP. or just hit edit and apply without changing the IP. it will then be marked as active.

supposed to be it should detect the modem to be active after some time right?

[FullyBorked]

What IP are you monitoring for each gateway?  If you turn off monitoring will it come online?

[tong2x]

1.1.1.1 and google DNS IPs.

yes there would be access... though since this is a 5G modem, sometimes I have to actually restart the modem but once it is online, the monitoring IP status would not change.
have to click edit save without actually changing anything will make it online
as if monitoring IP is sort of "blocked", denied or indefinitely set to "down" until a complete restart of the monitoring service.

[FullyBorked]

1.1.1.1 and google DNS IPs.

yes there would be access... though since this is a 5G modem, sometimes I have to actually restart the modem but once it is online, the monitoring IP status would not change.
have to click edit save without actually changing anything will make it online
as if monitoring IP is sort of "blocked" denied indefinitely.

Interesting, I have a somewhat similar setup cable (primary) 5G modem (backup).  I have had something similar happen but just once.  My cable was out for nearly 12 hours due to storm damage, when it was restored the firewall simply would not see it as an active connection with monitoring enabled.  After a few reboots of everything it finally started working again.  Sounds like maybe you are hitting this same "bug?" more often.  Oddly enough when this happened to me I could see the ping traffic in the firewall live log.  Not sure exactly what happened, but hasn't happened since even when rebooting either the cable modem or the 5g modem. 

[tong2x]

might be related

https://forum.opnsense.org/index.php?topic=29824.0

having the wan monitoring being down even after the connection is restored

[tong2x]

there is a patch out for testing...

# opnsense-patch e8d42b6

patch created by @franco
needs to be executed in the console, have already applied it and seems to have fixed the issue in may test.
please test the patch out if possible.

thread with similar issue
https://forum.opnsense.org/index.php?topic=29824.0
github bug report
https://github.com/opnsense/core/issues/5956