After moving to the new non-JWT sbsecret key format, REST calls authenticated with the service-role key intermittently return 401 with proxystatus PostgREST and error PGRST303 ("JWT issued at future"). The odd part: the client only ever sends the opaque sbsecret_ key, never a JWT, so the usual "clock skew on a freshly-issued Auth JWT" explanation does not apply. The same request retried about 1.4 seconds later succeeds, and the pattern fires in bursts for several users. Moving the deployment region closer to the project region did not change it, and failures came through Cloudflare colos already local to the project region.