Your sample (TicTacToe) fails the same way on watchOS 27.2. I changed only the bundle IDs and added the UIScene manifest that tvOS 27 requires. On the watch, the advertiser logs: -[_NWAdvertiser updateFlows:] Listener skipping advertise flows due to unsatisfied path with policy drop and rapportd never receives an ADVERTISE request for the service. On watchOS 26.6 the same app gets Added listener flow ID → ADVERTISE: Start advertise → Upgrading agentClient to listener.

Yes. It’s an existing app whose watchOS app worked with the Apple TV on watchOS 26 and fails on watchOS 27. I’ve reproduced it on watchOS 27.0.1 (24R365) and watchOS 27.2 (24S118) on an Apple Watch Series 10. The same build works on an Apple Watch Series 7 running watchOS 26.6 (23U67). The bug is FB25280603. I’ve attached sysdiagnoses from both the watch and the Apple TV with the Network Diagnostics profile installed, taken right after reproducing.