Issues with OpenWRT routers at a location

I am setting up a new router for family members after they received fiber, so I needed a box with a SFP port (for the fiber), Wifi 6, and OpenWRT. BananaPI R3 ticked all the right boxes so acquired one and set it up. There were several issues along the way among others, but mostly got it setup working.

Unfortunately it randomly freezes, and I haven't been able to pinpoint why. When the router freezes the wireless goes off and no ethernet port respond to any packets so it has to be power cycled (no amount of waiting changes anything). It seems to be happening at random hours even when the network isn't being heavily used (such as during the night) and at random intervals. I tried troubleshooting, saving the system logs to the SD card looking through them to see if there is anything that might explain why it happens, but couldn't find anything out of the ordinary. The only thing that might give a hint is that at one point I disabled the 5 GHz network and left it off for a while and the BananaPI-R3 didn't crash in that time period, but that might be coincidence.

I live in a different city so troubleshooting happens when I travel down which makes it a slow process, I decided therefore to take my Redmi AX6000 with uboot mod that has been working great at my place for several months and switch it out with the BananaPI-R3. The only changes in configuration I made was to replace my SSID and password and configure the correct VLANS for the fiber connection. I was surprised to see the Redmi AX6000 exhibiting the same behaviour as the BananaPI-R3 with random freezes (although in my short experience maybe a tad more rarely). They previously had a Netgear R7800 with OpenWRT I had setup and that one didn't exhibit such behaviour.

As mentioned I can only troubleshoot rarely as it requires me to travel down to their city, so I need advice and suggestions what I can look into and try to see if I can figure out why the routers are freezing up when I am traveling down.

Those are running on snapshot not stable. This is not a good choice for that use case. Also, the bpi-r3 needs heatsinks and fan cooling or else it randomly crashes due to over temp.

The Redmi AX6000 is not supported on stable yet either.

Installing luci-app-watchcat would allow you to reboot the router on loss of internet connection or every 24h. But a cron job might be better so you can time it at 3am for example so it doesn't reboot on them during the day when they are using it.

I think the best solution would be to get a router that runs on stable. Here is a list of openwrt routers that currently support 802.11ax. Bear in mind newly supported devices still have issues here and there. Other alternatives would be name brand routers or forks like gl-inet.

A possible workaround for the fiber / SFP aspect would be to get a media converter. If you search for "Fiber to Ethernet Media Converter" on Amazon (or other marketplace) you will find many low-cost options - some of which even come with the SFP module included. Just make sure you select the model that has the correct SFP ( Single Mode or Multi-Mode fiber ).

This would give you an ethernet handoff for the WAN connection thus increasing your list of routers to choose from.