Remote Desktop on Mac: login fails, and my Quest 3 shows on mobile but not on web

Meta Quest Remote Desktop on my Mac fails at login every time. It shows "Something went wrong. Please wait 2-5 minutes and try again." Waiting never helps. The failure is instant, so it is not really a rate limit.

The browser sign-in part works fine. It is the hand back to the app that fails. The app log says the login failed because a value came back as null while it was verifying my credentials.

I think I know why. My Quest 3 shows up correctly in the Meta Horizon mobile app under Devices, and in Accounts Center on my phone. But on the web, my account page says it cannot find any devices associated with my Meta account. Same account, no account switching.

I also cannot open a support ticket, because the support form cannot find my device either. My serial gets rejected and signing in shows the same no devices message.

Has anyone seen this? Happy to share the full log with a moderator.