Constant "gateway range likely lacks support" logs

I understand the actual log entry is fine for a server node, but I’m getting them every 10 seconds

tailscale/unknown,now 1.14.6 amd64 [installed]

Oct 04 09:27:44 host tailscaled[770]: [RATELIMIT] format(“netcheck: probePortMapServices: %v”) (2 dropped)
Oct 04 09:27:44 host tailscaled[770]: netcheck: probePortMapServices: skipping portmap; gateway range likely lacks support
Oct 04 09:27:45 host tailscaled[770]: netcheck: probePortMapServices: skipping portmap; gateway range likely lacks support
Oct 04 09:27:45 host tailscaled[770]: [RATELIMIT] format(“netcheck: probePortMapServices: %v”)
Oct 04 09:27:54 host tailscaled[770]: [RATELIMIT] format(“netcheck: probePortMapServices: %v”) (2 dropped)

etc.

Seems quite chatty?