I just experienced this.
I rebooted the first time since installing Tailscale and was not able to access my Unraid locally.
Just by coincidence I saw the node up in Tailscale and successfully tried the Tailscale IP.
Current state: Enabling Use Tailscale Subnets disables access to Unraid on the local ip immediately.
So I can't have both now... I had both before the first reboot after installing the Tailscale plugin.
There should be some way to fix this?
Also... I would suggest to add a warning to the Use Tailscale Subnets which says breaks local access on reboot until this is fixed.
I believe not everyone is able to troubleshoot this and many users don't have a Monitor hooked up - leaving them with an unreachable and unusable Unraid instance after installing Tailscale and enabling the Use Tailscale Subnets feature.