Tailscale shouldn't advertise a route that is local to the machine. This is a routing loop. The way SR route distribution works in Tailscale is that you accept all routes or nothing. Routing platforms have the concept of route filters to prevent accepting an advertised route that would create a loop.
There are hacky ways around this without having to deal with metrics (just advertise a /23 instead of a /24 and the /24 will be selected by default). But if you've got contiguous subnets you may not be able to clobber the additional address space just to avoid the route.
There are hacky ways around this without having to deal with metrics (just advertise a /23 instead of a /24 and the /24 will be selected by default). But if you've got contiguous subnets you may not be able to clobber the additional address space just to avoid the route.