Guest interface not brought up automatically

Installing and Using OpenWrt
1

Using Netgear RAX120v2 and newest snapshot, with added guest wifi (done basically by following the OpenWrt wiki, just add new network interface, firewall zone, wifi ssid, config being basically from the template). Recently I started having issue that the guest network interface is not being brought up automatically. First happened on build 27350, unfortunately I do not remember what was the previous build number I used that was still running good, but should be roughly no older than 4 weeks.

The issue presented itself as devices on guest wifi not getting IP. Assigning static IP on the devices still gave no connection to router or the outside world. While poking around on the router I saw the following status:

ubus call network.interface.guest status
{
        "up": false,
        "pending": false,
        "available": false,
        "autostart": true,
        "dynamic": false,
        "proto": "static",
        "data": {

        },
        "errors": [
                {
                        "subsystem": "interface",
                        "code": "NO_DEVICE"
                }
        ]
}

Whenever this happens, I can easily bring up the interface by calling:

ubus call network.interface.guest down
ubus call network.interface.guest up

and then everything works flawless, devices get IP from DHCP and are connected to internet, but I am wondering why I have to do it in the first place.

Background info:

  • all config under /etc/config has been unchanged for 6+ months, most of it for much longer
  • a sysupgrade has been done roughly every 4-6 weeks, without keeping config (that is, sysupgrade itself wipes everything to default, pull in config files after) - always the same procedure
  • no issue like this for a year before build 27350 (and possibly around 4 weeks before that, I do not remember build number of the previous one I used)
  • the wifi that is in lan network (together with lan port bridge) never has this issue. Seems like the guest interface might be missing some trigger to be started up?
  • the issue is intermittent. Sometimes the interface starts up with fresh reboot of router, sometimes it does not. Sometimes the interface goes down and stays down after ath11k firmware crash (a whole another topic), sometimes it stays up. Point being - I have not been able to correlate interface not being brought up to anything else. Even fresh cold boot does not always bring the interface up.
  • the error code "NO_DEVICE" does not help me much, as I understand it is normal for no devices to be defined in this guest network; it is in /etc/config/wireless where the connection is made for specific wifi to be in specific network

Looking for help on how to troubleshoot this one. I have seen quite a lot of commits on main branch for netifd in the past few weeks, it made me curious if maybe some kind of bug could have been introduced? Would appreciate if anyone has pointers on what to investigate or maybe somebody has a similar issue.

Thank you!