TailScale virtual network adapter creates a private mesh thus acting like a firewall and blocking multicast traffic. something NDI relies on heavily with mDNS. so even if it was allowed it would cause jitter and dropped frames all over the place. so (and i don't use tailscale for remote productions so i would dig deeper in this) i would either have tailscale ignore multicast traffic and or setup NDI using static runs with discovery service if local or use NDI Bridge that uses a specialize protocol like SRT and keep tailscale away from it. No matter what Tailscale will kill your NDI traffic due to latency. I could be wrong but scanning the tailscale docs it seems others ahve issue with any type of real-time traffic and or multicast so defenitly get it away from the ndi traffic.