Apple Watch Series 5 Fitness app is not syncing with Apple TV after tvOS 18.4 update

After the TV OS 18.4 update (and 18.5) the Fitness app just hangs after starting the app from Apple TV and selecting my profile, and then hitting ok on my watch (Apple Watch Series 5). It just spins. And spins. And spins.

Did all the quick fixes re: power cycling, same network, Bluetooth cycling, removing devices or removing profiles, selecting other. Zip. The only work around is starting the workout from my phone and Air Playing it to the Apple TV.

Any suggestions? Is this a known bug? It was working on 18.3 so I can confidently think it’s an update bug.

[Re-Titled by Moderator]