It’s hard to determine why since we can’t see your config, but from the logs, it looks like it never resolved your wireguard peer’s IP address. If it’s a hostname, make sure there’s no typo and that you can actually resolve it from the router (or your connected client).
From a command line:
# nslookup peer.host.name
Then, it’s mwan3 that’s turning the process down. I’ve found mwan3 to be a bit on the aggressive side (especially for “mobile” network connection monitoring), Try disabling that until you have your connectivity figured out:
From the shell:
# /etc/init.d/mwan3 stop && /etc/init.d/mwan3 disable
If you can’t or don’t want to use the shell, you’ll have to do this through the LuCI UI (http://192.168.8.1/cgi-bin/luci/). Log in there, select system → startup → mwan3 → Stop/Disable. It’s also possible to do this per-interface in GL’s UI (Network → MultiWAN), but it doesn’t survive a reboot. There’s a thread about this particular bug
Once everything’s resolved, you can re-enable mwan3 if you want/need it. Disabling mwan3 seems to mess with the UI’s internet reporting and the LED’s strength meter. It will falsely report there’s no connection or signal strength