A friend who lives in Russia was using Tailscale to connect to an exit node placed elsewhere to communicate with family via Signal etc. Now when they connect to the control server the requests give a 451 'unavailable for legal reasons' error. Probably a self-hosted control server like Headscale might circumvent this censorship for some time, but the friend is not technical enough (and understandably afraid) to manage this.
This has been going on for a while. A year or so ago I remember Tailscale was blocking downloads of their applications from Russian IPs. HTTP 451 means "unavailable for legal reasons" so I imagine this is Tailscale trying to cover its soft spots.
Can confirm. Many paid VPNs are not reliable enough as Roskomnadzor is successfully targeting them. I though that by deploying Tailscale exit node on my own server I could overcome this. Alas, not anymore.