[6.12] Upgrade to 6.12 breaks access when using Tailscale

Premise:

- I am using Tailscale to access my Unraid server (UI, SMB, SSH, everything)

- I have no access to real hardware. I am in a different country.

- I have upgraded to 6.12.

- After reboot I lost access to my Unraid server. I don't know how to get access back.

Description:

After I went to Unraid UI, I saw that there is a new version and I decided to upgrade as I am doing often.

After server reboot I could not access my server anymore.

I have started debugging...

I saw that server is still in Unraid network and I can ping it. But 80, 443, 22 ports and SMB were not accesible. That was weird.

I used nmap to scan all open ports and saw that 23 (telnet) port is open.

I have installed telnet on my MacOS and accessed terminal through 23 port.

Running ss -tpln showed that ssh and http servers are listening, but seems they were listening on a wrong IP.

I then went and read Change Log for new Unraid version (6.12) and read about networking changes and followed provided link.

Unfortunately all these links tell you how to fix Tailscale if you have access to WebUI, which I do not. And I cannot go and connect monitor to my Unraid server or something as I am in a different country.

I believe that this is a bug as an upgrade should not break existing setups.

And I need help with this problem. I do not have access to WebUI. How do I do required steps through terminal?

Thank you.