topic Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5) in Security

Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

TT_Vert — Fri, 30 Jan 2026 17:24:49 GMT

Reset devices, removed from app and attempted to re-add but get T009
Nest connect 10' from door so range isn't an issue
Phone on same WLAN, entire SSID is 2.4ghz ONLY, and airplane mode (Not that that "should" matter)
All other nest devices work fine,
I can communicate the nest connects on LAN via PC, on 2.4ghz.
For the sake of argument I did restart the wireless APs

Given both went offline around the same time (and nothin else on same network did) I have to assume it's a nest/google issue here.

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

KevinGR — Thu, 05 Feb 2026 01:59:06 GMT

Hi @TT_Vert,

Thank you for posting in the community. I’m sorry to hear that your two Nest x Yale Locks went offline and are now showing a T009 error when you try to reconnect them. I understand how difficult it can be when your security devices aren't working properly, and I appreciate the troubleshooting steps you’ve already taken. Since the problem persists after resetting and removing the devices, it is possible your router is blocking specific settings required for the connection. We recommend contacting your Internet Service Provider (ISP) for further assistance in ensuring your network configuration isn't preventing your devices from syncing.

I’ve listed the recommended configurations below for you to share with them.

Enable 802.11 b/g/n if you have an 802.11 ac router.
Set your Wi-Fi router's DHCP lease time to at least 2 hours.
Enable IPv6.
On your Wi-Fi router, turn on multicast, if you're adding additional Nest devices.
You can find more information about the Summary of recommended settings at the link.

Additionally, to help you further, could you please provide the steps you have taken to reset your Nest x Yale Lock?

I'll be waiting for your reply.

Best regards,

Kevin.

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

TT_Vert — Wed, 04 Feb 2026 03:51:11 GMT

I also tried putting these on two separate networks and same thing (Comcast and T-Mobile). It's not blocked traffic

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

KevinGR — Thu, 05 Feb 2026 03:25:52 GMT

Hi @TT_Vert,

Thank you for your reply. I appreciate you trying those different network connections. To assist you further, could you please provide the specific steps you took when attempting to reset your two Nest x Yale Locks?

I'll be waiting for your reply.

Best regards,

Kevin.

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

MikeB54 — Wed, 11 Feb 2026 01:57:14 GMT

I have this exact same issue. I don't see how IPv6 has anything to do with this, but to humor tech support I reconfigured my network and now the test-ipv6.com site gives me a 10/10. That, however, made no difference. I still get the message at the end of the setup that says Failed to add Nest x Yale Lock to account.

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

TT_Vert — Wed, 11 Feb 2026 02:19:34 GMT

IPv6 won't cause this. They really have no idea, not one of them. At the end of the day, I just fully reset them and left them for a day and then tried again. Surprisingly they were able to be added w/o any issue. If you have the same error, I'd reset both of them. I also removed my nest connects and readded them but I doubt that is necessary. I was always able to ping the connects and I do not block outbound traffic so I knew the issue was something on their side.

Dave

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

MikeB54 — Wed, 11 Feb 2026 16:47:26 GMT

I resolved this by factory resetting both of my locks using the reset button on the back of the PCB and the Nest Connects they were connected to. Took about an hour which was less time than what I spent online yesterday with a support assistant who was adamant that I had to have a fully functional IPv6 setup.

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

KevinGR — Thu, 12 Feb 2026 03:40:00 GMT

Hi folks,

Thank you for your reply. I’m glad to hear your Nest x Yale Locks are working again after the troubleshooting steps. I appreciate your effort in resolving the issue. If you have any other questions, please don't hesitate to reach out; we are always happy to help.

Best regards,

Kevin.

Re: Both locks went offline, tried everything but eventually reset. Now getting T009 (15.5)

TT_Vert — Thu, 12 Feb 2026 03:44:09 GMT

Good to hear