Can't see Openthread Border Router from different Phones

[cunning wedge]

Background:
HAOS is installed as a VM on Proxmox
HAOS has 2 NICs, Primary and secondary IoT only VLAN
I have a SLZB-MRU1 connected via PoE Ethernet (IoT VLAN)
I have a dedicated Wifi AP on the same IoT VLAN. IPv4 traffic pings around fine.
This is a completely virgin installation. I bought the SLZB and an two Ikea sensors to dip my toes into Thread/Matter

I've installed OTBR (beta) and MatterServer, and they appear to start with no real errors or anything. Both pointed to IoT VLAN.
HAOS Shows the preferred network and it looks good to me.

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Issue: I cannot see the OpenThread Border Router from either of two Android phones. Both report "No Thread Networks"

What I've done to investigate:
Tried to verify IPv6 config isn't an issue, though I am very new to IPv6 (I know IPv4 pretty well though)

I've added my PC to the same VLAN via wifi, and I can see Router Advertisements from the HAOS MAC, and I can see that the same interface inside HAOS (using ip -6 addr ) is correctly using the IoT VLAN interface

Wireshark capture from PC on same IoT WLAN as HAOS/OTBR/MatterServer/SLZB

[cunning wedge]

(yes the timestamps are off, I went back in to take them and did it in the wrong order - the errors are still the same 🙂 )

[cunning wedge]

I'm worried it's something with accept_ra on proxmox even, but I just don't know what to test to see what's not working. I don't understand how the OTBR "found"

[cunning wedge]

This is from my phone, so I'm apparently getting an IPv6 address. I don't have DHCPv6 enabled on my router, so it must be one of them automatic locallish ones.

[cyan ivy]

fyi i also have a perfectly functional thread network including matter devices and sometimes my phone can't find the thread network either, all of the devices work though.

[cunning wedge]

That's interesting.. are you able to connect devices to a border router you can't see? If so, thread really is magic 🙂

(this is my first router, first thread device, so I have no idea what further fun awaits me. So far, they don't connect)

[cyan ivy]

Home assistant can find the border router api, but my phone can't find the thread network. It really shows that thread is still much younger than zigbee. Just because my phone cannot see the network, that doesn't mean that the device you want to connect won't. What thread devices do you have?

[cunning wedge]

I need to do more testing. To answer your question, it's an ikea bulb.

I changed the interface the OTBR uses in its config to my regular LAN, swapped my phone to the regular lan, and it popped up (said it wasn't available but it was definitely progress). So even though I was seeing mDNS packets on the IoT VLAN when it was there, something either in proxmox or in HAOS is still not setup right. I don't know if it's hostname resolution or what.

[full elm]

Could it be that android has something saved to the linking those credentials/otbr thru the Lan and not the iot vlan and that is where the block is?

[cunning wedge]

I'll definitely have to test. That's been another pain point here - my actual phone won't let me choose a new thread border router. It's decided the google display I have is my preferred one and prefers not to let me use the one I want to use (despite the google device being unreachable). As a result, I've resurected an old android phone, blown out the cached data, and that one seems to sorta work? I hadn't considered that I'd need to blow out the config due to the LAN change, but that seems par for the course at this point.

[full elm]

So weird that google is such a mess with thread/matter, given their relationship with openthread.